On 10/31/22 20:27, Simon Glass wrote:
Hi Marek,
Hi,
On Sun, 30 Oct 2022 at 16:38, Marek Vasut <ma...@denx.de> wrote:
Logitech Unifying Receiver 046d:c52b bcdDevice 12.10 seems
sensitive about the first Get Descriptor request. If there
are any other requests in the same microframe, the device
reports bogus data, first of the descriptor parts is not
sent to the host. Wait over one microframe duration before
issuing subsequent requests to avoid probe failure with
this device, since it can be used to connect USB keyboards.
Signed-off-by: Marek Vasut <ma...@denx.de>
---
Cc: Janne Grunau <j...@jannau.net>
Cc: Mark Kettenis <kette...@openbsd.org>
---
common/usb.c | 11 +++++++++++
1 file changed, 11 insertions(+)
Is this device complying with the spec or is it broken?
In any case we need a way to enable/disable this as it will slow down
unaffected platforms.
This makes little difference, since anyone can plug such device into a
port and suddenly the platform is affected. We cannot really predict
what users have on their desks.
Specifically for this case, the logitech receiver seems to be a rather
common device.
I've also been wondering if (not with this patch) USB can move to
using the cyclic stuff to do its work, so we don't have to wait.
EHCI HCD already partly does, at least for storage, so yes, patches welcome.
