[U-Boot] [PATCH v5 02/19] usb: dwc2: Use separate input and output buffers

[Simon Glass]

Hi Marek,

On 1 April 2017 at 14:15, Marek Vasut <marex at denx.de> wrote:
> On 04/01/2017 08:05 PM, Simon Glass wrote:
>> On Raspberry Pi 2 and 3 a problem was noticed when enabling driver model
>> for USB: the cache invalidate after an incoming transfer does not seem to
>> work correctly.
>>
>> This may be a problem with the underlying caching implementation on armv7
>> and armv8 but this seems very unlikely. As a work-around, use separate
>> buffers for input and output. This ensures that the input buffer will not
>> hold dirty cache data.
>
> What do you think of this patch:
> [U-Boot] usb: dwc2: invalidate the dcache before starting the DMA

Yes that matches what I did as a hack. I didn't realise that the DMA
would go through the cache. Thanks for the pointer.

Regards,
Simon