[PATCH 2/6] usb_kbd: succeed even if no interrupt is pending

[Jason Wessel]

After the initial configuration some USB keyboard+mouse devices never
return any kind of event on the interrupt line.  In particular, the
device identified by "Cypress Cypress USB Keyboard / PS2 Mouse as
3f980000.usb/usb1/1-1/1-1.3/1-1.3:1.0/0003:04B4:0101.0001/input/input0"
never returns a data packet until the first external input event.

I found this was also true with some newer model Dell keyboards.

When the device is plugged into a xhci controller there is also no
point in waiting 5 seconds for a device that is never going to present
data, so the call to the interrupt service was changed to a
nonblocking operation for the controllers that support this.

With the patch applied, the rpi3 and rpi4 work well with the more
complex keyboard devices.

Signed-off-by: Jason Wessel <jason.wessel at windriver.com>
---
 common/usb_kbd.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/common/usb_kbd.c b/common/usb_kbd.c
index b316807844..3c0056e1b9 100644
--- a/common/usb_kbd.c
+++ b/common/usb_kbd.c
@@ -519,7 +519,9 @@ static int usb_kbd_probe_dev(struct usb_device *dev, unsigned int ifnum)
 			   1, 0, data->new, USB_KBD_BOOT_REPORT_SIZE) < 0) {
 #else
 	if (usb_int_msg(dev, data->intpipe, data->new, data->intpktsize,
-			data->intinterval, false) < 0) {
+			data->intinterval, true) < 0) {
+		/* Read first packet if the device provides it, else pick it up later */
+		return 1;
 #endif
 		printf("Failed to get keyboard state from device %04x:%04x\n",
 		       dev->descriptor.idVendor, dev->descriptor.idProduct);
-- 
2.17.1