On 2022-09-26 01:52:37 +0200, Marek Vasut wrote: > On 8/29/22 08:31, Janne Grunau wrote: > > Fixes probing of various keyboards with DWC3 as integrated into Apple > > silicon SoCs. The problem appears to be requesting more data than the > > devices's bMaxPacketSize0 of 8. Older Logitech unifying receivers > > (bcdDevice 12.03 or 12.10) are for eaxample affected. > > > > Signed-off-by: Janne Grunau <j...@jannau.net> > > Tested-by: Thomas Glanzmann <tho...@glanzmann.de> > > --- > > common/usb.c | 8 +++++--- > > 1 file changed, 5 insertions(+), 3 deletions(-) > > > > diff --git a/common/usb.c b/common/usb.c > > index 6fcf1e8428e9..48a310e8599d 100644 > > --- a/common/usb.c > > +++ b/common/usb.c > > @@ -993,10 +993,12 @@ static int usb_setup_descriptor(struct usb_device > > *dev, bool do_read) > > * > > * At least the DWC2 controller needs to be programmed with > > * the number of packets in addition to the number of bytes. > > - * A request for 64 bytes of data with the maxpacket guessed > > - * as 64 (above) yields a request for 1 packet. > > + * Requesting more than 8 bytes causes probing errors on the > > + * DWC3 controller integrated into Apple silicon SoCs with > > + * devices with bMaxPacketSize0 of 8. So limit the read request > > + * to the used size of 8 bytes. > > */ > > - err = get_descriptor_len(dev, 64, 8); > > + err = get_descriptor_len(dev, 8, 8); > > if (err) > > return err; > > } > > Sorry for the delay. > > Can you be more specific about those logitech receivers ?
In my case it's a device a little bit larger than a USB-A plug. ~7mm heigh black plastic case with "logitech" written on the end and and their unifying logo in orange on a side (idVendor: 0x046d, idProduct: 0xc52b, bcdDevice: 12.03). Russell has one with bcdDevice: 12.10 The problem is not limited to the logitech receivers. It reproduces for other keyboards with bMaxPacketSize0 == 8 as well. I suspect it affects all devices with bMaxPacketSize0 == 8. Keyboards are simply the type of device those breakage is noticed inside u-boot / efi bootloaders on desktop class devices and don't transfer that much data so that bMaxPacketSize0 == 8 doesn't hurt. > I might have one > of those devices, and I have DWC3 in i.MX8MP and i.MX8MQ, as well as ZynqMP, > so I should be able to try and trigger the problem. Can you share the > reproducer test case for this problem ? The device is not detected. It is not listed as detected usb device during u-boot's USB probing. If the device is a keyboard or you have a matching logitech wireless keyboard it will not work to interrupt the auto boot or on the u-boot prompt. > If the problem is specific to the Apple instance of the controller, > maybe we need some sort of quirk instead ? The code looks evidently broken to me. The comment says that we can only expect to receive a single packet. We request 64 bytes but devices might have a bMaxPacketSize0 of 8. Requesting more than 8 bytes looks also unnecessary as we are only interested in bMaxPacketSize0 which is within the first 8 bytes of the device descriptor. Thanks Janne
