aboutsummaryrefslogtreecommitdiff
path: root/drivers/tty
AgeCommit message (Collapse)Author
2016-10-30Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Mostly simple overlapping changes. For example, David Ahern's adjacency list revamp in 'net-next' conflicted with an adjacency list traversal bug fix in 'net'. Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-28tty: serial_core: fix NULL struct tty pointer access in uart_write_wakeupRob Herring
Since commit 761ed4a94582ab29 ("tty: serial_core: convert uart_close to use tty_port_close"), the serial console is broken on various systems and typing "reboot" splats the following on the serial console: INIT: Sending p[ 427.863916] BUG: unable to handle kernel NULL pointer dereference at 00000000000001e0 [ 427.885156] IP: [] tty_wakeup+0xc/0x70 [ 427.898337] PGD 0 [ 427.902051] [ 427.907498] Oops: 0000 [#1] PREEMPT SMP [ 427.917635] Modules linked in: nfsv3 nfs_acl nfs fscache lockd sunrpc grace edd af_packet cpufreq_conservative cpufreq_userspace cpufreq_powersave fuse loop md_mod dm_mod joydev hid_generic usbhid ipmi_ssif ohci_pci ohci_hcd ehci_pci ehci_hcd e1000e ptp firewire_ohci edac_core pps_core tpm_infineon sp5100_tco firewire_core acpi_cpufreq serio_raw pcspkr fjes usbcore shpchp edac_mce_amd tpm_tis ipmi_si tpm_tis_core i2c_piix4 k10temp sg ipmi_msghandler tpm sr_mod button cdrom kvm_amd kvm irqbypass crc_itu_t ast ttm drm_kms_helper drm fb_sys_fops sysimgblt sysfillrect syscopyarea i2c_algo_bit scsi_dh_rdac scsi_dh_alua scsi_dh_emc scsi_dh_hp_sw ata_generic pata_atiixp [ 428.054179] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.9.0-rc1-1.g73e3f23-default #1 [ 428.072868] Hardware name: System manufacturer System Product Name/KGP(M)E-D16, BIOS 0902 12/03/2010 [ 428.094755] task: ffffffffa2c0d500 task.stack: ffffffffa2c00000 [ 428.109717] RIP: 0010:[] [] tty_wakeup+0xc/0x70 [ 428.128407] RSP: 0018:ffff9a1a5fc03df8 EFLAGS: 00010086 [ 428.142184] RAX: ffff9a1857258000 RBX: ffffffffa3050ea0 RCX: 0000000000000000 [ 428.159649] RDX: 000000000000001b RSI: 0000000000000000 RDI: 0000000000000000 [ 428.177109] RBP: ffff9a1a5fc03e08 R08: 0000000000000000 R09: 0000000000000000 [ 428.194547] R10: 0000000000021c77 R11: 0000000000000000 R12: ffff9a1857258000 [ 428.212002] R13: 0000000000000000 R14: 0000000000000020 R15: 0000000000000020 [ 428.229481] FS: 0000000000000000(0000) GS:ffff9a1a5fc00000(0000) knlGS:0000000000000000 [ 428.248938] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 428.263726] CR2: 00000000000001e0 CR3: 0000000390c06000 CR4: 00000000000006f0 [ 428.281331] Stack: [ 428.288696] ffffffffa3050ea0 ffff9a1857258000 ffff9a1a5fc03e18 ffffffffa24e0ab1 [ 428.307064] ffff9a1a5fc03e40 ffffffffa24e8865 ffffffffa3050ea0 00000000000000c2 [ 428.325456] 0000000000000046 ffff9a1a5fc03e78 ffffffffa24e8a5f ffffffffa3050ea0 [ 428.343905] Call Trace: [ 428.352319] [ 428.356216] [] uart_write_wakeup+0x21/0x30 The problem is for console ports, the serial port is not shutdown and interrupts may fire after the struct tty is gone. Simply calling the tty_port helper tty_port_tty_wakeup instead of tty_wakeup directly will ensure there is a valid struct tty. Fixes: 761ed4a94582ab29 ("tty: serial_core: convert uart_close to use tty_port_close") Reported-by: Borislav Petkov <bp@alien8.de> Reported-by: Mike Galbraith <mgalbraith@suse.de> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-serial@vger.kernel.org Signed-off-by: Rob Herring <robh@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-28tty: serial_core: Fix serial console crash on port shutdownGeert Uytterhoeven
The port->console flag is always false, as uart_console() is called before the serial console has been registered. Hence for a serial port used as the console, uart_tty_port_shutdown() will still be called when userspace closes the port, powering it down. This may lead to a system lock up when the serial console driver writes to the serial port's registers. To fix this, move the setting of port->console after the call to uart_configure_port(), which registers the serial console. Fixes: 761ed4a94582ab29 ("tty: serial_core: convert uart_close to use tty_port_close") Reported-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Rob Herring <robh@kernel.org> Tested-by: Mugunthan V N <mugunthanvnm@ti.com> Tested-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se> [robh: rebased on tty-linus] Signed-off-by: Rob Herring <robh@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-28tty/serial: at91: fix hardware handshake on Atmel platformsRichard Genoud
After commit 1cf6e8fc8341 ("tty/serial: at91: fix RTS line management when hardware handshake is enabled"), the hardware handshake wasn't functional anymore on Atmel platforms (beside SAMA5D2). To understand why, one has to understand the flag ATMEL_US_USMODE_HWHS first: Before commit 1cf6e8fc8341 ("tty/serial: at91: fix RTS line management when hardware handshake is enabled"), this flag was never set. Thus, the CTS/RTS where only handled by serial_core (and everything worked just fine). This commit introduced the use of the ATMEL_US_USMODE_HWHS flag, enabling it for all boards when the user space enables flow control. When the ATMEL_US_USMODE_HWHS is set, the Atmel USART controller handles a part of the flow control job: - disable the transmitter when the CTS pin gets high. - drive the RTS pin high when the DMA buffer transfer is completed or PDC RX buffer full or RX FIFO is beyond threshold. (depending on the controller version). NB: This feature is *not* mandatory for the flow control to work. (Nevertheless, it's very useful if low latencies are needed.) Now, the specifics of the ATMEL_US_USMODE_HWHS flag: - For platforms with DMAC and no FIFOs (sam9x25, sam9x35, sama5D3, sama5D4, sam9g15, sam9g25, sam9g35)* this feature simply doesn't work. ( source: https://lkml.org/lkml/2016/9/7/598 ) Tested it on sam9g35, the RTS pins always stays up, even when RXEN=1 or a new DMA transfer descriptor is set. => ATMEL_US_USMODE_HWHS must not be used for those platforms - For platforms with a PDC (sam926{0,1,3}, sam9g10, sam9g20, sam9g45, sam9g46)*, there's another kind of problem. Once the flag ATMEL_US_USMODE_HWHS is set, the RTS pin can't be driven anymore via RTSEN/RTSDIS in USART Control Register. The RTS pin can only be driven by enabling/disabling the receiver or setting RCR=RNCR=0 in the PDC (Receive (Next) Counter Register). => Doing this is beyond the scope of this patch and could add other bugs, so the original (and working) behaviour should be set for those platforms (meaning ATMEL_US_USMODE_HWHS flag should be unset). - For platforms with a FIFO (sama5d2)*, the RTS pin is driven according to the RX FIFO thresholds, and can be also driven by RTSEN/RTSDIS in USART Control Register. No problem here. (This was the use case of commit 1cf6e8fc8341 ("tty/serial: at91: fix RTS line management when hardware handshake is enabled")) NB: If the CTS pin declared as a GPIO in the DTS, (for instance cts-gpios = <&pioA PIN_PB31 GPIO_ACTIVE_LOW>), the transmitter will be disabled. => ATMEL_US_USMODE_HWHS flag can be set for this platform ONLY IF the CTS pin is not a GPIO. So, the only case when ATMEL_US_USMODE_HWHS can be enabled is when (atmel_use_fifo(port) && !mctrl_gpio_to_gpiod(atmel_port->gpios, UART_GPIO_CTS)) Tested on all Atmel USART controller flavours: AT91SAM9G35-CM (DMAC flavour), AT91SAM9G20-EK (PDC flavour), SAMA5D2xplained (FIFO flavour). * the list may not be exhaustive Cc: <stable@vger.kernel.org> #4.4+ (beware, missing atmel_port variable) Fixes: 1cf6e8fc8341 ("tty/serial: at91: fix RTS line management when hardware handshake is enabled") Signed-off-by: Richard Genoud <richard.genoud@gmail.com> Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Acked-by: Cyrille Pitchen <cyrille.pitchen@atmel.com> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-27vt: clear selection before resizingScot Doyle
When resizing a vt its selection may exceed the new size, resulting in an invalid memory access [1]. Clear the selection before resizing. [1] http://lkml.kernel.org/r/CACT4Y+acDTwy4umEvf5ROBGiRJNrxHN4Cn5szCXE5Jw-d1B=Xw@mail.gmail.com Reported-and-tested-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Scot Doyle <lkml14@scotdoyle.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-27sc16is7xx: always write state when configuring GPIO as an outputFrancois Berder
The regmap_update first reads the IOState register and then triggers a write if needed. However, GPIOS might be configured as an input so the read to IOState on this GPIO is the current state which might be random. Signed-off-by: Francois Berder <Francois.Berder@imgtec.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-27tty: serial: 8250: 8250_core: NXP SC16C2552 workaroundSteve Shih
NXP SC16C2552 requires that we always write a reset to the RX FIFO and TX FIFO whenever we enable the FIFOs Cc: xe-kernel@external.cisco.com Signed-off-by: Steve Shih <sshih@cisco.com> Signed-off-by: David Singleton <davsingl@cisco.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-27tty: limit terminal size to 4M charsDmitry Vyukov
Size of kmalloc() in vc_do_resize() is controlled by user. Too large kmalloc() size triggers WARNING message on console. Put a reasonable upper bound on terminal size to prevent WARNINGs. Signed-off-by: Dmitry Vyukov <dvyukov@google.com> CC: David Rientjes <rientjes@google.com> Cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: Peter Hurley <peter@hurleysoftware.com> Cc: linux-kernel@vger.kernel.org Cc: syzkaller@googlegroups.com Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-27tty: serial: fsl_lpuart: Fix Tx DMA edge caseAaron Brice
In the case where head == 0 on the circular buffer, there should be one DMA buffer, not two. The second zero-length buffer would break the lpuart driver, transfer would never complete. Signed-off-by: Aaron Brice <aaron.brice@datasoft.com> Acked-by: Stefan Agner <stefan@agner.ch> Tested-by: Stefan Agner <stefan@agner.ch> Tested-by: Bhuvanchandra DV <bhuvanchandra.dv@toradex.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-27serial: 8250_lpss: enable MSI for sureAndy Shevchenko
The commit 4fe0d154880b ("PCI: Use positive flags in pci_alloc_irq_vectors()") replaces flags from negative to positive values which makes mandatory to have the last argument in pci_alloc_irq_vectors() non-zero (if we want to be no-op). This basically drops MSI enabling in 8250_lpss driver. Restore desired behaviour in 8250_lpss by passing PCI_IRQ_ALL_TYPES instead of 0 to pci_alloc_irq_vectors(). Fixes: 60a9244a5d14 ("serial: 8250_lpss: enable MSI for Intel Quark") Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Bryan O'Donoghue <pure.logic@nexus-software.ie> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-27serial: core: fix console problems on uart_closeRob Herring
Commit 761ed4a94582 ('tty: serial_core: convert uart_close to use tty_port_close') started setting the ttyport console flag for serial drivers. This is causing crashes, hangs, or garbage output on several platforms because the serial shutdown is skipped and IRQs are left enabled. Partially revert commit 761ed4a94582 and drop reporting UART tty_ports as a console leaving the console handling to the serial_core as it was before. Fixes: 761ed4a94582ab29 ("tty: serial_core: convert uart_close to use tty_port_close") Reported-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se> Reported-by: Mike Galbraith <umgwanakikbuti@gmail.com> Reported-by: Mugunthan V N <mugunthanvnm@ti.com> Cc: Peter Hurley <peter@hurleysoftware.com> Cc: Geert Uytterhoeven <geert+renesas@glider.be> Cc: Alan Cox <alan@linux.intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: linux-serial@vger.kernel.org Signed-off-by: Rob Herring <robh@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-27serial: 8250_uniphier: fix clearing divisor latch access bitMasahiro Yamada
At this point, 'value' is always a byte, then this code is clearing bit 15, which is already clear. I meant to clear bit 7. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reported-by: Denys Vlasenko <dvlasenk@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-27serial: 8250_uniphier: fix more unterminated stringDenys Vlasenko
Commit 1681d2116c96 ("serial: 8250_uniphier: add "\n" at the end of error log") missed this. Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com> [masahiro: add commit log] Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-27serial: pch_uart: add terminate entry for dmi_system_id tablesWei Yongjun
Make sure dmi_system_id tables are NULL terminated. Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com> Acked-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-27serial: xuartps: Add new compatible string for ZynqMPNava kishore Manne
This patch Adds the new compatible string for ZynqMP SoC. Signed-off-by: Nava kishore Manne <navam@xilinx.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-27serial: SERIAL_STM32 should depend on HAS_DMAGeert Uytterhoeven
If NO_DMA=y: drivers/built-in.o: In function `stm32_serial_remove': stm32-usart.c:(.text+0xcea1a): undefined reference to `bad_dma_ops' stm32-usart.c:(.text+0xcea7a): undefined reference to `bad_dma_ops' Add a dependency on HAS_DMA to fix this. Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Alexandre Torgue <alexandre.torgue@st.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-27serial: stm32: Fix comparisons with undefined registerGeert Uytterhoeven
drivers/tty/serial/stm32-usart.c: In function ‘stm32_receive_chars’: drivers/tty/serial/stm32-usart.c:130: warning: comparison is always true due to limited range of data type drivers/tty/serial/stm32-usart.c: In function ‘stm32_tx_dma_complete’: drivers/tty/serial/stm32-usart.c:177: warning: comparison is always false due to limited range of data type stm32_usart_offsets.icr is u8, while UNDEF_REG = ~0 is int, and thus 0xffffffff. As all registers in stm32_usart_offsets are u8, change the definition of UNDEF_REG to 0xff to fix this. Fixes: ada8618ff3bfe183 ("serial: stm32: adding support for stm32f7") Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-27tty: vt, fix bogus division in csi_JJiri Slaby
In csi_J(3), the third parameter of scr_memsetw (vc_screenbuf_size) is divided by 2 inappropriatelly. But scr_memsetw expects size, not count, because it divides the size by 2 on its own before doing actual memset-by-words. So remove the bogus division. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Petr Písař <ppisar@redhat.com> Fixes: f8df13e0a9 (tty: Clean console safely) Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-20net: use core MTU range checking in WAN driversJarod Wilson
- set min/max_mtu in all hdlc drivers, remove hdlc_change_mtu - sent max_mtu in lec driver, remove lec_change_mtu - set min/max_mtu in x25_asy driver CC: netdev@vger.kernel.org CC: Krzysztof Halasa <khc@pm.waw.pl> CC: Krzysztof Halasa <khalasa@piap.pl> CC: Jan "Yenya" Kasprzak <kas@fi.muni.cz> CC: Francois Romieu <romieu@fr.zoreil.com> CC: Kevin Curtis <kevin.curtis@farsite.co.uk> CC: Zhao Qiang <qiang.zhao@nxp.com> Signed-off-by: Jarod Wilson <jarod@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-20net: use core MTU range checking in wireless driversJarod Wilson
- set max_mtu in wil6210 driver - set max_mtu in atmel driver - set min/max_mtu in cisco airo driver, remove airo_change_mtu - set min/max_mtu in ipw2100/ipw2200 drivers, remove libipw_change_mtu - set min/max_mtu in p80211netdev, remove wlan_change_mtu - set min/max_mtu in net/mac80211/iface.c and remove ieee80211_change_mtu - set min/max_mtu in wimax/i2400m and remove i2400m_change_mtu - set min/max_mtu in intersil/hostap and remove prism2_change_mtu - set min/max_mtu in intersil/orinoco - set min/max_mtu in tty/n_gsm and remove gsm_change_mtu CC: netdev@vger.kernel.org CC: linux-wireless@vger.kernel.org CC: Maya Erez <qca_merez@qca.qualcomm.com> CC: Simon Kelley <simon@thekelleys.org.uk> CC: Stanislav Yakovlev <stas.yakovlev@gmail.com> CC: Johannes Berg <johannes@sipsolutions.net> CC: Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com> Signed-off-by: Jarod Wilson <jarod@redhat.com> Acked-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-11kthread: kthread worker API cleanupPetr Mladek
A good practice is to prefix the names of functions by the name of the subsystem. The kthread worker API is a mix of classic kthreads and workqueues. Each worker has a dedicated kthread. It runs a generic function that process queued works. It is implemented as part of the kthread subsystem. This patch renames the existing kthread worker API to use the corresponding name from the workqueues API prefixed by kthread_: __init_kthread_worker() -> __kthread_init_worker() init_kthread_worker() -> kthread_init_worker() init_kthread_work() -> kthread_init_work() insert_kthread_work() -> kthread_insert_work() queue_kthread_work() -> kthread_queue_work() flush_kthread_work() -> kthread_flush_work() flush_kthread_worker() -> kthread_flush_worker() Note that the names of DEFINE_KTHREAD_WORK*() macros stay as they are. It is common that the "DEFINE_" prefix has precedence over the subsystem names. Note that INIT() macros and init() functions use different naming scheme. There is no good solution. There are several reasons for this solution: + "init" in the function names stands for the verb "initialize" aka "initialize worker". While "INIT" in the macro names stands for the noun "INITIALIZER" aka "worker initializer". + INIT() macros are used only in DEFINE() macros + init() functions are used close to the other kthread() functions. It looks much better if all the functions use the same scheme. + There will be also kthread_destroy_worker() that will be used close to kthread_cancel_work(). It is related to the init() function. Again it looks better if all functions use the same naming scheme. + there are several precedents for such init() function names, e.g. amd_iommu_init_device(), free_area_init_node(), jump_label_init_type(), regmap_init_mmio_clk(), + It is not an argument but it was inconsistent even before. [arnd@arndb.de: fix linux-next merge conflict] Link: http://lkml.kernel.org/r/20160908135724.1311726-1-arnd@arndb.de Link: http://lkml.kernel.org/r/1470754545-17632-3-git-send-email-pmladek@suse.com Suggested-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Petr Mladek <pmladek@suse.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Tejun Heo <tj@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Borislav Petkov <bp@suse.de> Cc: Michal Hocko <mhocko@suse.cz> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-10Merge branch 'printk-cleanups'Linus Torvalds
Merge my system logging cleanups, triggered by the broken '\n' patches. The line continuation handling has been broken basically forever, and the code to handle the system log records was both confusing and dubious. And it would do entirely the wrong thing unless you always had a terminating newline, partly because it couldn't actually see whether a message was marked KERN_CONT or not (but partly because the LOG_CONT handling in the recording code was rather confusing too). This re-introduces a real semantically meaningful KERN_CONT, and fixes the few places I noticed where it was missing. There are probably more missing cases, since KERN_CONT hasn't actually had any semantic meaning for at least four years (other than the checkpatch meaning of "no log level necessary, this is a continuation line"). This also allows the combination of KERN_CONT and a log level. In that case the log level will be ignored if the merging with a previous line is successful, but if a new record is needed, that new record will now get the right log level. That also means that you can at least in theory combine KERN_CONT with the "pr_info()" style helpers, although any use of pr_fmt() prefixing would make that just result in a mess, of course (the prefix would end up in the middle of a continuing line). * printk-cleanups: printk: make reading the kernel log flush pending lines printk: re-organize log_output() to be more legible printk: split out core logging code into helper function printk: reinstate KERN_CONT for printing continuation lines
2016-10-09printk: reinstate KERN_CONT for printing continuation linesLinus Torvalds
Long long ago the kernel log buffer was a buffered stream of bytes, very much like stdio in user space. It supported log levels by scanning the stream and noticing the log level markers at the beginning of each line, but if you wanted to print a partial line in multiple chunks, you just did multiple printk() calls, and it just automatically worked. Except when it didn't, and you had very confusing output when different lines got all mixed up with each other. Then you got fragment lines mixing with each other, or with non-fragment lines, because it was traditionally impossible to tell whether a printk() call was a continuation or not. To at least help clarify the issue of continuation lines, we added a KERN_CONT marker back in 2007 to mark continuation lines: 474925277671 ("printk: add KERN_CONT annotation"). That continuation marker was initially an empty string, and didn't actuall make any semantic difference. But it at least made it possible to annotate the source code, and have check-patch notice that a printk() didn't need or want a log level marker, because it was a continuation of a previous line. To avoid the ambiguity between a continuation line that had that KERN_CONT marker, and a printk with no level information at all, we then in 2009 made KERN_CONT be a real log level marker which meant that we could now reliably tell the difference between the two cases. 5fd29d6ccbc9 ("printk: clean up handling of log-levels and newlines") and we could take advantage of that to make sure we didn't mix up continuation lines with lines that just didn't have any loglevel at all. Then, in 2012, the kernel log buffer was changed to be a "record" based log, where each line was a record that has a loglevel and a timestamp. You can see the beginning of that conversion in commits e11fea92e13f ("kmsg: export printk records to the /dev/kmsg interface") 7ff9554bb578 ("printk: convert byte-buffer to variable-length record buffer") with a number of follow-up commits to fix some painful fallout from that conversion. Over all, it took a couple of months to sort out most of it. But the upside was that you could have concurrent readers (and writers) of the kernel log and not have lines with mixed output in them. And one particular pain-point for the record-based kernel logging was exactly the fragmentary lines that are generated in smaller chunks. In order to still log them as one recrod, the continuation lines need to be attached to the previous record properly. However the explicit continuation record marker that is actually useful for this exact case was actually removed in aroundm the same time by commit 61e99ab8e35a ("printk: remove the now unnecessary "C" annotation for KERN_CONT") due to the incorrect belief that KERN_CONT wasn't meaningful. The ambiguity between "is this a continuation line" or "is this a plain printk with no log level information" was reintroduced, and in fact became an even bigger pain point because there was now the whole record-level merging of kernel messages going on. This patch reinstates the KERN_CONT as a real non-empty string marker, so that the ambiguity is fixed once again. But it's not a plain revert of that original removal: in the four years since we made KERN_CONT an empty string again, not only has the format of the log level markers changed, we've also had some usage changes in this area. For example, some ACPI code seems to use KERN_CONT _together_ with a log level, and now uses both the KERN_CONT marker and (for example) a KERN_INFO marker to show that it's an informational continuation of a line. Which is actually not a bad idea - if the continuation line cannot be attached to its predecessor, without the log level information we don't know what log level to assign to it (and we traditionally just assigned it the default loglevel). So having both a log level and the KERN_CONT marker is not necessarily a bad idea, but it does mean that we need to actually iterate over potentially multiple markers, rather than just a single one. Also, since KERN_CONT was still conceptually needed, and encouraged, but didn't actually _do_ anything, we've also had the reverse problem: rather than having too many annotations it has too few, and there is bit rot with code that no longer marks the continuation lines with the KERN_CONT marker. So this patch not only re-instates the non-empty KERN_CONT marker, it also fixes up the cases of bit-rot I noticed in my own logs. There are probably other cases where KERN_CONT will be needed to be added, either because it is new code that never dealt with the need for KERN_CONT, or old code that has bitrotted without anybody noticing. That said, we should strive to avoid the need for KERN_CONT. It does result in real problems for logging, and should generally not be seen as a good feature. If we some day can get rid of the feature entirely, because nobody does any fragmented printk calls, that would be lovely. But until that point, let's at mark the code that relies on the hacky multi-fragment kernel printk's. Not only does it avoid the ambiguity, it also annotates code as "maybe this would be good to fix some day". (That said, particularly during single-threaded bootup, the downsides of KERN_CONT are very limited. Things get much hairier when you have multiple threads going on and user level reading and writing logs too). Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-03Merge tag 'tty-4.9-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty and serial updates from Greg KH: "Here is the big tty and serial patch set for 4.9-rc1. It also includes some drivers/dma/ changes, as those were needed by some serial drivers, and they were all acked by the DMA maintainer. Also in here is the long-suffering ACPI SPCR patchset, which was passed around from maintainer to maintainer like a hot-potato. Seems I was the sucker^Wlucky one. All of those patches have been acked by the various subsystem maintainers as well. All of this has been in linux-next with no reported issues" * tag 'tty-4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (111 commits) Revert "serial: pl011: add console matching function" MAINTAINERS: update entry for atmel_serial driver serial: pl011: add console matching function ARM64: ACPI: enable ACPI_SPCR_TABLE ACPI: parse SPCR and enable matching console of/serial: move earlycon early_param handling to serial Revert "drivers/tty: Explicitly pass current to show_stack" tty: amba-pl011: Don't complain on -EPROBE_DEFER when no irq nios2: dts: 10m50: Add tx-threshold parameter serial: 8250: Set Altera 16550 TX FIFO Threshold serial: 8250: of: Load TX FIFO Threshold from DT Documentation: dt: serial: Add TX FIFO threshold parameter drivers/tty: Explicitly pass current to show_stack serial: imx: Fix DCD reading serial: stm32: mark symbols static where possible serial: xuartps: Add some register initialisation to cdns_early_console_setup() serial: xuartps: Removed unwanted checks while reading the error conditions serial: xuartps: Rewrite the interrupt handling logic serial: stm32: use mapbase instead of membase for DMA tty/serial: atmel: fix fractional baud rate computation ...
2016-10-03Merge tag 'char-misc-4.9-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc Pull char/misc driver updates from Greg KH: "Here's the "big" char and misc driver update for 4.9-rc1. Lots of little things here, all over the driver tree for subsystems that flow through me. Nothing major that I can discern, full details are in the shortlog. All have been in the linux-next tree with no reported issues" * tag 'char-misc-4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (144 commits) drivers/misc/hpilo: Changes to support new security states in iLO5 FW at25: fix debug and error messaging misc/genwqe: ensure zero initialization vme: fake: remove unexpected unlock in fake_master_set() vme: fake: mark symbols static where possible spmi: pmic-arb: Return an error code if sanity check fails Drivers: hv: get rid of id in struct vmbus_channel Drivers: hv: make VMBus bus ids persistent mcb: Add a dma_device to mcb_device mcb: Enable PCI bus mastering by default mei: stop the stall timer worker if not needed clk: probe common clock drivers earlier vme: fake: fix build for 64-bit dma_addr_t ttyprintk: Neaten and simplify printing mei: me: add kaby point device ids coresight: tmc: mark symbols static where possible coresight: perf: deal with error condition properly Drivers: hv: hv_util: Avoid dynamic allocation in time synch fpga manager: Add hardware dependency to Zynq driver Drivers: hv: utils: Support TimeSync version 4.0 protocol samples. ...
2016-10-02Merge branch 'device-properties'Rafael J. Wysocki
* device-properties: serial: 8250_dw: Add quirk for APM X-Gene SoC ACPI / LPSS: Provide build-in properties of the UART ACPI / APD: Provide build-in properties of the UART driver core: Don't leak secondary fwnode on device removal
2016-09-30Revert "serial: pl011: add console matching function"Greg Kroah-Hartman
This reverts commit 8b8f347d3a4859d22567f3b8e5bb4a69b1089739 as it causes build errors in linux-next Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Aleksey Makarov <aleksey.makarov@linaro.org> Cc: Peter Hurley <peter@hurleysoftware.com> Cc: Russell King <rmk+kernel@armlinux.org.uk> Cc: Christopher Covington <cov@codeaurora.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-28serial: pl011: add console matching functionAleksey Makarov
This patch adds function pl011_console_match() that implements method match of struct console. It allows to match consoles against data specified in a string, for example taken from command line or compiled by ACPI SPCR table handler. Signed-off-by: Aleksey Makarov <aleksey.makarov@linaro.org> Reviewed-by: Peter Hurley <peter@hurleysoftware.com> Acked-by: Russell King <rmk+kernel@armlinux.org.uk> Tested-by: Christopher Covington <cov@codeaurora.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-28ACPI: parse SPCR and enable matching consoleAleksey Makarov
'ARM Server Base Boot Requiremets' [1] mentions SPCR (Serial Port Console Redirection Table) [2] as a mandatory ACPI table that specifies the configuration of serial console. Defer initialization of DT earlycon until ACPI/DT decision is made. Parse the ACPI SPCR table, setup earlycon if required, enable specified console. Thanks to Peter Hurley for explaining how this should work. [1] http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.den0044a/index.html [2] https://msdn.microsoft.com/en-us/library/windows/hardware/dn639132(v=vs.85).aspx Signed-off-by: Aleksey Makarov <aleksey.makarov@linaro.org> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Peter Hurley <peter@hurleysoftware.com> Tested-by: Kefeng Wang <wangkefeng.wang@huawei.com> Tested-by: Christopher Covington <cov@codeaurora.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-28of/serial: move earlycon early_param handling to serialLeif Lindholm
We have multiple "earlycon" early_param handlers - merge the DT one into the main earlycon one. It's a cleanup that also will be useful to defer setting up DT console until ACPI/DT decision is made. Rename the exported function to avoid clashing with the function from arch/microblaze/kernel/prom.c Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org> Signed-off-by: Aleksey Makarov <aleksey.makarov@linaro.org> Acked-by: Rob Herring <robh@kernel.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Peter Hurley <peter@hurleysoftware.com> Tested-by: Kefeng Wang <wangkefeng.wang@huawei.com> Tested-by: Christopher Covington <cov@codeaurora.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-28Revert "drivers/tty: Explicitly pass current to show_stack"Greg Kroah-Hartman
This reverts commit 9f12cea96f47f98d612a0a0b84f950a0163731bf. Mark writes: Unfortunately, this patch will result in erroneous stack traces on some architectures. Sorry about this; I should have verified this more thoroughly before sending the series out. Please drop the patch at your earliest convenience. Cc: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-27tty: amba-pl011: Don't complain on -EPROBE_DEFER when no irqKefeng Wang
Don't complain on -EPROBE_DEFER when attempting to get the irq. the driver probe will be retried later. Cc: Russell King <linux@armlinux.org.uk> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-27serial: 8250: Set Altera 16550 TX FIFO ThresholdThor Thayer
The Altera 16550 soft IP UART requires 2 additional registers for TX FIFO threshold support. These 2 registers enable the TX FIFO Low Watermark and set the TX FIFO Low Watermark. Set the TX FIFO threshold to the FIFO size - tx_loadsz. Signed-off-by: Thor Thayer <tthayer@opensource.altera.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-27serial: 8250: of: Load TX FIFO Threshold from DTThor Thayer
Initialize the tx_loadsz parameter from passed in devicetree tx-threshold parameter. The tx_loadsz is calculated as the number of bytes to fill FIFO when tx-threshold is triggered. Signed-off-by: Thor Thayer <tthayer@opensource.altera.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-27drivers/tty: Explicitly pass current to show_stackMark Rutland
As noted in commit: 81539169f283329f ("x86/dumpstack: Remove NULL task pointer convention") ... having a NULL task parameter imply current leads to subtle bugs in stack walking code (so far seen on both 86 and arm64), makes callsites harder to read, and is unnecessary as all callers have access to current. As a step towards removing the problematic NULL-implies-current idiom entirely, have the sysrq code explicitly pass current to show_stack. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: linux-kernel@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-27serial: imx: Fix DCD readingSascha Hauer
The USR2_DCDIN bit is tested for in register usr1. As the name suggests the usr2 register should be used instead. This fixes reading the Carrier detect status. Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> Fixes: 90ebc4838666 ("serial: imx: repair and complete handshaking") Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Cc: <stable@vger.kernel.org> # 4.5+ Reviewed-by: Fabio Estevam <fabio.estevam@nxp.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-27serial: stm32: mark symbols static where possibleBaoyou Xie
We get 2 warnings when building kernel with W=1: drivers/tty/serial/stm32-usart.c:63:5: warning: no previous prototype for 'stm32_pending_rx' [-Wmissing-prototypes] drivers/tty/serial/stm32-usart.c:88:15: warning: no previous prototype for 'stm32_get_char' [-Wmissing-prototypes] In fact, these two functions are only used in the file in which they are declared and don't need a declaration, but can be made static. So this patch marks these functions with 'static'. Signed-off-by: Baoyou Xie <baoyou.xie@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-27serial: xuartps: Add some register initialisation to cdns_early_console_setup()Scott Telford
Add initialisation of control register and baud rate to cdns_early_console_setup(), required when running kernel standalone without a boot loader. Baud rate is only initialised when specified in earlycon command-line option, otherwise it is assumed this has been set by a boot loader. Updated Documentation/kernel-parameters.txt accordingly. Signed-off-by: Scott Telford <stelford@cadence.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-27serial: xuartps: Removed unwanted checks while reading the error conditionsNava kishore Manne
This patch Remove the unwated checks while reading the parity,framing, overrun and Break detection errors. Signed-off-by: Nava kishore Manne <navam@xilinx.com> Signed-off-by: Michal Simek <michal.simek@xilinx.com> [stelford@cadence.com: cherry picked from https://github.com/Xilinx/linux-xlnx commit b1cf74970df5470ffbc8e7876a9edf5e3498ef94] Signed-off-by: Scott Telford <stelford@cadence.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-27serial: xuartps: Rewrite the interrupt handling logicAnirudha Sarangi
The existing interrupt handling logic has following issues. - Upon a parity error with default configuration, the control never comes out of the ISR thereby hanging Linux. - The error handling logic around framing and parity error are buggy. There are chances that the errors will never be captured. This patch ensures that the status registers are cleared on all cases so that a hang situation never arises. Signed-off-by: Anirudha Sarangi <anirudh@xilinx.com> Signed-off-by: Michal Simek <michal.simek@xilinx.com> [stelford@cadence.com: cherry picked from https://github.com/Xilinx/linux-xlnx commit ac297e20d399850d7a8e373b6eccf2e183c15165 with manual conflict resolution] Signed-off-by: Scott Telford <stelford@cadence.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-27serial: stm32: use mapbase instead of membase for DMAArnd Bergmann
Building this driver with a 64-bit dma_addr_t type results in a compiler warning: drivers/tty/serial/stm32-usart.c: In function 'stm32_of_dma_rx_probe': drivers/tty/serial/stm32-usart.c:746:20: error: cast from pointer to integer of different size [-Werror=pointer-to-int-cast] drivers/tty/serial/stm32-usart.c: In function 'stm32_of_dma_tx_probe': drivers/tty/serial/stm32-usart.c:818:20: error: cast from pointer to integer of different size [-Werror=pointer-to-int-cast] While the type conversion here is harmless, this hints at a different problem: we pass an __iomem pointer into a DMA engine, which expects a phys_addr_t. This happens to work because stm32 has no MMU and ioremap() is an identity mapping here, but it's still an incorrect API use. Using dma_addr_t is doubly wrong here, because that would be the result of dma_map_single() rather than the physical address. Using the mapbase instead fixes multiple issues: - the warning is gone - we don't go through ioremap in error - the cast is gone, making it use the correct resource_size_t/phys_addr_t type in the process. Fixes: 3489187204eb ("serial: stm32: adding dma support") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Gerald Baeza <gerald.baeza@st.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-27tty/serial: atmel: fix fractional baud rate computationAlexey Starikovskiy
The problem with previous code was it rounded values in wrong place and produced wrong baud rate in some cases. Signed-off-by: Alexey Starikovskiy <aystarik@gmail.com> [nicolas.ferre@atmel.com: port to newer kernel and add commit log] Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com> Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com> Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-22serial: xuartps: Do not enable parity error interruptAnirudha Sarangi
The patch makes changes not to enable parity error interrupt. With the current implementation, each parity error results in two distinct interrupts (almost always). The first one is normal parity error interrupt with no data in the fifo and the second one is a proper Rx interrupt with the received data in the fifo. By disabling parity error interrupt we still ensure handling of parity errors as for the Rx fifo interrupt the parity error still shows up in the interrupt status register. Considering the fact that the by default INPCK and IGNPAR are not set, this is the optimal implementation for parity error handling. Signed-off-by: Anirudha Sarangi <anirudh@xilinx.com> Signed-off-by: Michal Simek <michal.simek@xilinx.com> [stelford@cadence.com: cherry picked from https://github.com/Xilinx/linux-xlnx commit bf9f610b445e2c9ed33c41e1e0e30b43be4e1f97 with manual conflict resolution] Signed-off-by: Scott Telford <stelford@cadence.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-22serial: stm32: fix uart enable managementAlexandre TORGUE
Signed-off-by: Gerald Baeza <gerald.baeza@st.com> Signed-off-by: Alexandre TORGUE <alexandre.torgue@st.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-22serial: stm32: fix spin_lock managementAlexandre TORGUE
Signed-off-by: Gerald Baeza <gerald.baeza@st.com> Signed-off-by: Alexandre TORGUE <alexandre.torgue@st.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-22serial: stm32: adding dma supportAlexandre TORGUE
This patch adds dma mode support for rx and tx with pio mode as fallback in case of dma error. Signed-off-by: Gerald Baeza <gerald.baeza@st.com> Signed-off-by: Alexandre TORGUE <alexandre.torgue@st.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-22serial: stm32: clock disabling managementAlexandre TORGUE
Keep the clock enabled at the end of stm32_init_port but disable it in stm32_serial_remove. Note that stm32_pm function is there to manage the clock at runtime. Signed-off-by: Gerald Baeza <gerald.baeza@st.com> Signed-off-by: Alexandre TORGUE <alexandre.torgue@st.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-22serial: stm32: correct flow control property spellingAlexandre TORGUE
"st,hw-flow-ctrl" property is documented in device tree binding whereas "auto-flow-control" was used in the code. The driver is now aligned with the binding name "st,hw-flow-ctrl". Signed-off-by: Gerald Baeza <gerald.baeza@st.com> Signed-off-by: Alexandre TORGUE <alexandre.torgue@st.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-22serial: stm32: disable tx and rx during shutdownAlexandre TORGUE
Signed-off-by: Gerald Baeza <gerald.baeza@st.com> Signed-off-by: Alexandre TORGUE <alexandre.torgue@st.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-22serial: stm32: header file creationAlexandre TORGUE
Signed-off-by: Gerald Baeza <gerald.baeza@st.com> Signed-off-by: Alexandre TORGUE <alexandre.torgue@st.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>