diff options
| -rw-r--r-- | drivers/acpi/spcr.c | 36 | ||||
| -rw-r--r-- | drivers/tty/serial/amba-pl011.c | 37 | ||||
| -rw-r--r-- | include/linux/acpi.h | 1 |
3 files changed, 54 insertions, 20 deletions
diff --git a/drivers/acpi/spcr.c b/drivers/acpi/spcr.c index 4ac3e06b41d8..98aa8c808a33 100644 --- a/drivers/acpi/spcr.c +++ b/drivers/acpi/spcr.c @@ -17,6 +17,16 @@ #include <linux/serial_core.h> /* + * Erratum 44 for QDF2432v1 and QDF2400v1 SoCs describes the BUSY bit as + * occasionally getting stuck as 1. To avoid the potential for a hang, check + * TXFE == 0 instead of BUSY == 1. This may not be suitable for all UART + * implementations, so only do so if an affected platform is detected in + * parse_spcr(). + */ +bool qdf2400_e44_present; +EXPORT_SYMBOL(qdf2400_e44_present); + +/* * Some Qualcomm Datacenter Technologies SoCs have a defective UART BUSY bit. * Detect them by examining the OEM fields in the SPCR header, similiar to PCI * quirk detection in pci_mcfg.c. @@ -147,8 +157,30 @@ int __init parse_spcr(bool earlycon) goto done; } - if (qdf2400_erratum_44_present(&table->header)) - uart = "qdf2400_e44"; + /* + * If the E44 erratum is required, then we need to tell the pl011 + * driver to implement the work-around. + * + * The global variable is used by the probe function when it + * creates the UARTs, whether or not they're used as a console. + * + * If the user specifies "traditional" earlycon, the qdf2400_e44 + * console name matches the EARLYCON_DECLARE() statement, and + * SPCR is not used. Parameter "earlycon" is false. + * + * If the user specifies "SPCR" earlycon, then we need to update + * the console name so that it also says "qdf2400_e44". Parameter + * "earlycon" is true. + * + * For consistency, if we change the console name, then we do it + * for everyone, not just earlycon. + */ + if (qdf2400_erratum_44_present(&table->header)) { + qdf2400_e44_present = true; + if (earlycon) + uart = "qdf2400_e44"; + } + if (xgene_8250_erratum_present(table)) iotype = "mmio32"; diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c index 8a857bb34fbb..1888d168a41c 100644 --- a/drivers/tty/serial/amba-pl011.c +++ b/drivers/tty/serial/amba-pl011.c @@ -142,15 +142,7 @@ static struct vendor_data vendor_sbsa = { .fixed_options = true, }; -/* - * Erratum 44 for QDF2432v1 and QDF2400v1 SoCs describes the BUSY bit as - * occasionally getting stuck as 1. To avoid the potential for a hang, check - * TXFE == 0 instead of BUSY == 1. This may not be suitable for all UART - * implementations, so only do so if an affected platform is detected in - * parse_spcr(). - */ -static bool qdf2400_e44_present = false; - +#ifdef CONFIG_ACPI_SPCR_TABLE static struct vendor_data vendor_qdt_qdf2400_e44 = { .reg_offset = pl011_std_offsets, .fr_busy = UART011_FR_TXFE, @@ -165,6 +157,7 @@ static struct vendor_data vendor_qdt_qdf2400_e44 = { .always_enabled = true, .fixed_options = true, }; +#endif static u16 pl011_st_offsets[REG_ARRAY_SIZE] = { [REG_DR] = UART01x_DR, @@ -2375,12 +2368,14 @@ static int __init pl011_console_match(struct console *co, char *name, int idx, resource_size_t addr; int i; - if (strcmp(name, "qdf2400_e44") == 0) { - pr_info_once("UART: Working around QDF2400 SoC erratum 44"); - qdf2400_e44_present = true; - } else if (strcmp(name, "pl011") != 0) { + /* + * Systems affected by the Qualcomm Technologies QDF2400 E44 erratum + * have a distinct console name, so make sure we check for that. + * The actual implementation of the erratum occurs in the probe + * function. + */ + if ((strcmp(name, "qdf2400_e44") != 0) && (strcmp(name, "pl011") != 0)) return -ENODEV; - } if (uart_parse_earlycon(options, &iotype, &addr, &options)) return -ENODEV; @@ -2734,11 +2729,17 @@ static int sbsa_uart_probe(struct platform_device *pdev) } uap->port.irq = ret; - uap->reg_offset = vendor_sbsa.reg_offset; - uap->vendor = qdf2400_e44_present ? - &vendor_qdt_qdf2400_e44 : &vendor_sbsa; +#ifdef CONFIG_ACPI_SPCR_TABLE + if (qdf2400_e44_present) { + dev_info(&pdev->dev, "working around QDF2400 SoC erratum 44\n"); + uap->vendor = &vendor_qdt_qdf2400_e44; + } else +#endif + uap->vendor = &vendor_sbsa; + + uap->reg_offset = uap->vendor->reg_offset; uap->fifosize = 32; - uap->port.iotype = vendor_sbsa.access_32b ? UPIO_MEM32 : UPIO_MEM; + uap->port.iotype = uap->vendor->access_32b ? UPIO_MEM32 : UPIO_MEM; uap->port.ops = &sbsa_uart_pops; uap->fixed_baud = baudrate; diff --git a/include/linux/acpi.h b/include/linux/acpi.h index c749eef1daa1..27b4b6615263 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -1209,6 +1209,7 @@ static inline bool acpi_has_watchdog(void) { return false; } #endif #ifdef CONFIG_ACPI_SPCR_TABLE +extern bool qdf2400_e44_present; int parse_spcr(bool earlycon); #else static inline int parse_spcr(bool earlycon) { return 0; } |