[U-Boot] [PATCH 3/7] usb: dwc2: Throttle the setup packet resending

Marek Vasut marex at denx.de
Wed May 4 23:21:10 CEST 2016


On 05/04/2016 07:08 PM, Stephen Warren wrote:
> On 05/03/2016 02:51 PM, Marek Vasut wrote:
>> Abort the request in case any of the tokens in the packet failed to
>> complete transfer 10 times. This is a precaution needed so that we
>> don't end in endless loop when scanning the bus with some braindead
>> devices.
> 
> Does this affect USB keyboards when SYS_USB_EVENT_POLL_VIA_CONTROL_EP is
> enabled? IIRC control transactions to HID devices can be held off for
> some duration based on polling intervals, and this patch might abort
> them early?

I didn't try this with keyboard, so I am not quite sure on this one.
Do you have RPi zero or somesuch on which you could try ?

btw are usb 1.1 keyboards supposed to work with DWC2 in U-Boot ?

> Or do we typically expect to use interrupt transfers for keyboards, so
> this isn't too relevant (although there are some platforms that enable
> SYS_USB_EVENT_POLL_VIA_CONTROL_EP). Maybe not DWC2 platforms though; I
> didn't check.

The platforms which enable POLL_VIA_CONTROL_EP are all chipidea otg, so
this should be fine.

-- 
Best regards,
Marek Vasut


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