tree 8eecaeefe68403924017cc5c526f0ea6afa15732
parent a06854a600f6ccb72f097d86a44688949b867906
author A Sun <as1033x@comcast.net> 1492070807 -0300
committer Mauro Carvalho Chehab <mchehab@s-opensource.com> 1496750328 -0300

[media] mceusb: TX -EPIPE (urb status = -32) lockup fix

Once IR blasting or mceusb device commands fail with mce_async_callback()
TX -EPIPE error, all subsequent TX to device then fail with the same error.
...
[  249.986174] mceusb 1-1.2:1.0: requesting 38000 HZ carrier
[  249.986210] mceusb 1-1.2:1.0: send request called (size=0x4)
[  249.986256] mceusb 1-1.2:1.0: send request complete (res=0)
[  249.986403] mceusb 1-1.2:1.0: Error: request urb status = -32 (TX HALT)
[  249.999885] mceusb 1-1.2:1.0: send request called (size=0x3)
[  249.999929] mceusb 1-1.2:1.0: send request complete (res=0)
[  250.000013] mceusb 1-1.2:1.0: Error: request urb status = -32 (TX HALT)
[  250.019830] mceusb 1-1.2:1.0: send request called (size=0x21)
[  250.019868] mceusb 1-1.2:1.0: send request complete (res=0)
[  250.020007] mceusb 1-1.2:1.0: Error: request urb status = -32 (TX HALT)
...

Fault simulation/injection is by executing the following USB operation
in a mceusb instrumented driver, prior to TX I/O.
    retval = usb_control_msg(ir->usbdev, usb_sndctrlpipe(ir->usbdev, 0),
	USB_REQ_SET_FEATURE, USB_RECIP_ENDPOINT,
	USB_ENDPOINT_HALT, usb_pipeendpoint(ir->pipe_out),
	NULL, 0, USB_CTRL_SET_TIMEOUT);
    dev_dbg(ir->dev, "set halt retval, %d", retval);

After setting halt state for the TX endpoint, perform an lirc "irsend"
to generate TX traffic to device. After the TX HALT, the patch restores
subsequent TX to working state.
...
[  508.009638] mceusb 1-1.2:1.0: send request called (size=0x3)
[  508.009697] mceusb 1-1.2:1.0: send request complete (res=0)
[  508.009847] mce_async_callback()
[  508.009864] mceusb 1-1.2:1.0: Error: request urb status = -32 (TX HALT)
[  508.009890] mceusb 1-1.2:1.0: kevent 0 scheduled
[  508.021552] mceusb 1-1.2:1.0: send request called (size=0x21)
[  508.021598] mceusb 1-1.2:1.0: send request complete (res=0)
[  508.021963] mce_async_callback()
[  508.021981] mceusb 1-1.2:1.0: tx data: 84 b0 0c 8c 0c 84 8c 0c 8c 0c 84 8c 0c 8c 0c 84 98 0c 98 0c 84 98 0c 8c 0c 84 8c 0c 8c 0c 81 8c 80 (length=33)
[  508.021997] mceusb 1-1.2:1.0: Raw IR data, 0 pulse/space samples
[  508.066627] mceusb 1-1.2:1.0: send request called (size=0x3)
[  508.066669] mceusb 1-1.2:1.0: send request complete (res=0)
[  508.066841] mce_async_callback()
[  508.066858] mceusb 1-1.2:1.0: tx data: 9f 08 03 (length=3)
...

Signed-off-by: A Sun <as1033x@comcast.net>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>