This change provides some extra time for some slow (or degraded) USB devices to become fully operational.
This code is the port to newest U-Boot of the fix from - "rayvt" (from [1]). Links: [1] - https://forum.doozan.com/read.php?3,35295,35295#msg-35295 [2] - https://www.dropbox.com/s/nrkrd1no63viuu8/uboot-bodhi-2016.05-timeoutTD.patch?dl=0 Signed-off-by: Lukasz Majewski <lu...@denx.de> [Unfortunately, the original patch [2] did not contain S-o-B from the original author - "rayvt"] --- common/usb.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/common/usb.c b/common/usb.c index 349e838f1d..305482b5bb 100644 --- a/common/usb.c +++ b/common/usb.c @@ -925,14 +925,20 @@ static int get_descriptor_len(struct usb_device *dev, int len, int expect_len) __maybe_unused struct usb_device_descriptor *desc; ALLOC_CACHE_ALIGN_BUFFER(unsigned char, tmpbuf, USB_BUFSIZ); int err; + int retry = 5; desc = (struct usb_device_descriptor *)tmpbuf; +again: err = usb_get_descriptor(dev, USB_DT_DEVICE, 0, desc, len); if (err < expect_len) { if (err < 0) { - printf("unable to get device descriptor (error=%d)\n", - err); + printf("unable to get device descriptor (error=%d) retry: %d\n", + err, retry); + mdelay(50); + if (--retry >= 0) + /* Some drives are just slow to wake up. */ + goto again; return err; } else { printf("USB device descriptor short read (expected %i, got %i)\n", -- 2.20.1
