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authorA Sun2019-07-14 22:51:26 -0400
committerMauro Carvalho Chehab2019-07-22 15:29:53 -0400
commit19d41a2899dcca7862af453d62a8e61933f3252d (patch)
treecb922ec85c4695647bc927c753d3bfc2c761f08c /drivers/media/rc/mceusb.c
parent765bb8610d305ee488b35d07e2a04ae52fb2df9c (diff)
media: mceusb: USB reset device following USB clear halt error
This patch schedules a USB reset device call following a USB clear halt error. The issues solved, and patch implementation, are similar to those found in drivers/hid/usbhid/hid-core.c. As seen on very rare occasions approximately one time per month (mceusb device 2304:0225 in this sample) Jul 27 2018 15:09:39 [59388.696941] mceusb 1-1.1.2:1.0: Error: urb status = -32 (RX HALT) [59388.698838] mceusb 1-1.1.2:1.0: rx clear halt error -32 the device can get into RX or TX HALT state where usb_clear_halt() also fails and also returns -EPIPE (HALT/STALL). After which, all further mceusb device control and data I/O always fail with HALT/STALL. Subsequently, the entire mceusb device no longer functions. Cause and problem replication conditions remain unknown. Further troubleshooting reveals usb_reset_device() restores mceusb device operation. Patch test 1: Hot unplugging the mceusb device triggers USB RX HALT and USB clear halt errors. A mceusb_dev_disconnect() call follows unplug. This patch's reset device call invokes an extra mceusb_dev_probe() mceusb_dev_disconnect() cycle, before the mceusb driver detaches. The additional probe/disconnect verifies the patch's device reset code executed. But note this patch is for USB clear halt error cases not caused by unplugging the mceusb device. Patch test 2: Simulate a RX HALT and a clear halt error with instrumented code in the driver. Jul 12 2019 19:41:18 [522745.263104] mceusb 1-1.3:1.0: set rx halt retval, 0 [522745.263943] mceusb 1-1.3:1.0: Error: rx urb status = -32 (RX HALT) [522745.263970] mceusb 1-1.3:1.0: kevent 1 scheduled [522745.264016] mceusb 1-1.3:1.0: kevent handler called (flags 0x2) [522745.272883] mceusb 1-1.3:1.0: rx clear halt status = 0 [522745.272917] mceusb 1-1.3:1.0: stuck RX HALT state requires USB Reset Device to clear [522745.273005] mceusb 1-1.3:1.0: mceusb_dev_disconnect called [522745.702815] usb 1-1.3: reset full-speed USB device number 14 using dwc_otg [522745.836812] mceusb 1-1.3:1.0: mceusb_dev_probe called [522745.836823] mceusb 1-1.3:1.0: acceptable bulk inbound endpoint found [522745.836832] mceusb 1-1.3:1.0: acceptable bulk outbound endpoint found ... The result matches what is expected when the device gets into a real rx clear halt error case by itself. This is the same sequence of messages when manually invoking the ./usbreset command line utility with an unpatched mceusb driver. Signed-off-by: A Sun <as1033x@comcast.net> Signed-off-by: Sean Young <sean@mess.org> Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Diffstat (limited to 'drivers/media/rc/mceusb.c')
-rw-r--r--drivers/media/rc/mceusb.c67
1 files changed, 55 insertions, 12 deletions
diff --git a/drivers/media/rc/mceusb.c b/drivers/media/rc/mceusb.c
index 4d5351ebb940..bc74c09ddeb6 100644
--- a/drivers/media/rc/mceusb.c
+++ b/drivers/media/rc/mceusb.c
@@ -461,6 +461,7 @@ struct mceusb_dev {
/* usb */
struct usb_device *usbdev;
+ struct usb_interface *usbintf;
struct urb *urb_in;
unsigned int pipe_in;
struct usb_endpoint_descriptor *usb_ep_out;
@@ -517,6 +518,7 @@ struct mceusb_dev {
unsigned long kevent_flags;
# define EVENT_TX_HALT 0
# define EVENT_RX_HALT 1
+# define EVENT_RST_PEND 31
};
/* MCE Device Command Strings, generally a port and command pair */
@@ -758,8 +760,15 @@ static void mceusb_dev_printdata(struct mceusb_dev *ir, u8 *buf, int buf_len,
static void mceusb_defer_kevent(struct mceusb_dev *ir, int kevent)
{
set_bit(kevent, &ir->kevent_flags);
+
+ if (test_bit(EVENT_RST_PEND, &ir->kevent_flags)) {
+ dev_dbg(ir->dev, "kevent %d dropped pending USB Reset Device",
+ kevent);
+ return;
+ }
+
if (!schedule_work(&ir->kevent))
- dev_err(ir->dev, "kevent %d may have been dropped", kevent);
+ dev_dbg(ir->dev, "kevent %d already scheduled", kevent);
else
dev_dbg(ir->dev, "kevent %d scheduled", kevent);
}
@@ -1398,28 +1407,59 @@ static void mceusb_deferred_kevent(struct work_struct *work)
container_of(work, struct mceusb_dev, kevent);
int status;
+ dev_err(ir->dev, "kevent handler called (flags 0x%lx)",
+ ir->kevent_flags);
+
+ if (test_bit(EVENT_RST_PEND, &ir->kevent_flags)) {
+ dev_err(ir->dev, "kevent handler canceled pending USB Reset Device");
+ return;
+ }
+
if (test_bit(EVENT_RX_HALT, &ir->kevent_flags)) {
usb_unlink_urb(ir->urb_in);
status = usb_clear_halt(ir->usbdev, ir->pipe_in);
+ dev_err(ir->dev, "rx clear halt status = %d", status);
if (status < 0) {
- dev_err(ir->dev, "rx clear halt error %d",
- status);
+ /*
+ * Unable to clear RX halt/stall.
+ * Will need to call usb_reset_device().
+ */
+ dev_err(ir->dev,
+ "stuck RX HALT state requires USB Reset Device to clear");
+ usb_queue_reset_device(ir->usbintf);
+ set_bit(EVENT_RST_PEND, &ir->kevent_flags);
+ clear_bit(EVENT_RX_HALT, &ir->kevent_flags);
+
+ /* Cancel all other error events and handlers */
+ clear_bit(EVENT_TX_HALT, &ir->kevent_flags);
+ return;
}
clear_bit(EVENT_RX_HALT, &ir->kevent_flags);
- if (status == 0) {
- status = usb_submit_urb(ir->urb_in, GFP_KERNEL);
- if (status < 0) {
- dev_err(ir->dev,
- "rx unhalt submit urb error %d",
- status);
- }
+ status = usb_submit_urb(ir->urb_in, GFP_KERNEL);
+ if (status < 0) {
+ dev_err(ir->dev, "rx unhalt submit urb error = %d",
+ status);
}
}
if (test_bit(EVENT_TX_HALT, &ir->kevent_flags)) {
status = usb_clear_halt(ir->usbdev, ir->pipe_out);
- if (status < 0)
- dev_err(ir->dev, "tx clear halt error %d", status);
+ dev_err(ir->dev, "tx clear halt status = %d", status);
+ if (status < 0) {
+ /*
+ * Unable to clear TX halt/stall.
+ * Will need to call usb_reset_device().
+ */
+ dev_err(ir->dev,
+ "stuck TX HALT state requires USB Reset Device to clear");
+ usb_queue_reset_device(ir->usbintf);
+ set_bit(EVENT_RST_PEND, &ir->kevent_flags);
+ clear_bit(EVENT_TX_HALT, &ir->kevent_flags);
+
+ /* Cancel all other error events and handlers */
+ clear_bit(EVENT_RX_HALT, &ir->kevent_flags);
+ return;
+ }
clear_bit(EVENT_TX_HALT, &ir->kevent_flags);
}
}
@@ -1581,6 +1621,7 @@ static int mceusb_dev_probe(struct usb_interface *intf,
if (!ir->urb_in)
goto urb_in_alloc_fail;
+ ir->usbintf = intf;
ir->usbdev = usb_get_dev(dev);
ir->dev = &intf->dev;
ir->len_in = maxp;
@@ -1688,6 +1729,8 @@ static void mceusb_dev_disconnect(struct usb_interface *intf)
struct usb_device *dev = interface_to_usbdev(intf);
struct mceusb_dev *ir = usb_get_intfdata(intf);
+ dev_dbg(&intf->dev, "%s called", __func__);
+
usb_set_intfdata(intf, NULL);
if (!ir)