[U-Boot] [PATCH V2 1/2] usb: dwc2: fix aligned buffer usage

[Stephen Warren]

On 03/09/2015 06:46 AM, Marek Vasut wrote:
> On Sunday, March 08, 2015 at 06:08:13 PM, Stephen Warren wrote:
>> The original aligned_buffer usage:
>> a) Uselessly copied data into the aligned buffer even for IN
>>     transactions. Fix this my making the copy conditional.
>> b) Always programmed the HW to transfer to/from the start of the aligned
>>     buffer. This worked fine for OUT transactions since the memcpy copied
>>     the OUT data to this location too. However, for large IN transactions,
>>     since the copy from the aligned buffer to the "client" buffer was
>>     deferred until after all chunks were transferred. it resulted in each
>>     chunk's transfer over-writing the data for the first transfer. Fix
>>     this by copying IN data as soon as it's received.
>>
>> Signed-off-by: Stephen Warren <swarren at wwwdotorg.org>
>
> Applied to u-boot-usb/topic/dwc2, thanks. I would like to see more
> testing from others if possible, otherwise this will go in after
> 2015.04 if you're fine with that.

Yes, that makes sense at this point in the cycle.

BTW, I should have mentioned the result of these on the RPi, although 
they're much the same as with the earlier patch you posted to support 
 >max_packet_size control transfers:

* I can enumerate a USB keyboard directly attached to the SoC, without 
intervening hub.

* If I enable USB keyboard support in U-Boot, and configure it to poll 
via the control EP or interrupt EP (I implemented the submit_interrupt 
function identically to submit_bulk), it will roughly work, except:

** The system usually hangs up very shortly after detecting the USB 
keyboard. Sometimes it lasts a long time though. This appears to be a 
hard hang; if I force the timer module to generate an IRQ, then 
typically I would see U-Boot spew the PC/SP/... when the IRQ fires. 
However, if the timer IRQ is scheduled to fire after the USB-related 
hang, nothing is printed. I need to try JTAG I guess.

** When polling via the interrupt EP, the character repeat is massively 
too fast; much faster than on e.g. NVIDIA Tegra Seaboard with the same 
keyboard polling option selected. It seems that USB IN transactions 
often repeat without actually writing to the IN data buffer, although I 
can't see any status in the registers indicating that the transaction 
was NAK'd/NYET'd/failed. I wonder if I need to manually delay 
transactions with this controller - do EHCI controllers hold off 
interrupt transactions automatically and only submit them to the bus at 
a low rate?