[U-Boot] [PATCH] usb: kbd: don't use int xfers when polling via ctrl xfers

[Stephen Warren <swarren@wwwdotorg.org>]

On 12/15/2015 05:42 PM, Marek Vasut wrote:
> On Wednesday, December 16, 2015 at 12:35:23 AM, Stephen Warren wrote:
>> On 11/13/2015 06:16 PM, Marek Vasut wrote:
>>> On Friday, November 13, 2015 at 09:34:09 PM, Stephen Warren wrote:
>>>> From: Stephen Warren <swarren@nvidia.com>
>>>>
>>>> When CONFIG_SYS_USB_EVENT_POLL_VIA_CONTROL_EP is enabled, use a
>>>> GET_REPORT control transfer to retrieve the initial state of the
>>>> keyboard. This matches the technique used to poll the keyboard state.
>>>> This is useful since it eliminates the remaining use of interrupt
>>>> transfers from the USB keyboard driver, which allows it to work with
>>>> USB HCD that don't support interrupt transfers.
>>>>
>>>> Cc: Hans de Goede <hdegoede@redhat.com>
>>>> Signed-off-by: Stephen Warren <swarren@nvidia.com>
>>>> ---
>>>> Are there any disadvantages to using control transfers over interrupt
>>>> transfers? I'm not aware of any, but I assume there must be a reason
>>>> that U-Boot typically uses interrupt transfers.
>>>
>>> I initially implemented the control EP polling because I had a keyboard
>>> which had issues with interrupt transfers.
>>>
>>> Reviewed-by: Marek Vasut <marex@denx.de>
>>
>> Did you intend someone else to apply this?
> 
> Is the discussion concluded already? I was under the impression that there
> was no general agreement.
> 
> Otherwise I can pick this of course.

The last comments in the thread were:

Hans de Goede wrote:
> Stephen Warren wrote:
>> However, I think that fixing the existing "use control transfers" support
>> so that it exclusively uses control transfers is still reasonable?
> 
> Ack, as long as we have it, we should fix it. I do believe we should get rid
> of it in the long run though.