linux-imx

usb: dwc2: host: do not delay retries for CONTROL IN transfers

When handling split transactions we will try to delay retry after
getting a NAK from the device. This works well for BULK transfers that
can be polled for essentially forever. Unfortunately, on slower systems
at boot time, when the kernel is busy enumerating all the devices (USB
or not), we issue a bunch of control requests (reading device
descriptors, etc). If we get a NAK for the IN part of the control
request and delay retry for too long (because the system is busy), we
may confuse the device when we finally get to reissue SSPLIT/CSPLIT IN
and the device will respond with STALL. As a result we end up with
failure to get device descriptor and will fail to enumerate the device:

[    3.428801] usb 2-1.2.1: new full-speed USB device number 9 using dwc2
[    3.508576] usb 2-1.2.1: device descriptor read/8, error -32
[    3.699150] usb 2-1.2.1: device descriptor read/8, error -32
[    3.891653] usb 2-1.2.1: new full-speed USB device number 10 using dwc2
[    3.968859] usb 2-1.2.1: device descriptor read/8, error -32
...

Let's not delay retries of split CONTROL IN transfers, as this allows us
to reliably enumerate devices at boot time.

Fixes: 38d2b5fb75c1 ("usb: dwc2: host: Don't retry NAKed transactions right away")
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>