Re: query on DWC3

From: sundeep subbaraya
Date: Tue Jan 06 2015 - 02:10:01 EST


Hi,

On Mon, Dec 22, 2014 at 9:42 PM, Felipe Balbi <balbi@xxxxxx> wrote:
> Hi again,
>
> On Mon, Dec 22, 2014 at 10:11:23AM -0600, Felipe Balbi wrote:
>> (please don't top-post)

Sure.

>>
>> On Sun, Dec 14, 2014 at 08:39:18AM +0530, sundeep subbaraya wrote:
>> > Hi Paul,
>> >
>> > As per my understanding, for BULK OUT we do queue a request with 512
>> > bytes length since we do not
>>
>> sometimes we _do_ know the size. In case of Mass Storage, we _know_ that
>> the first bulk out transfer will be 31-bytes (CBW), if we were to start
>> a 31-byte transfer, we would't receive anything.
>>
>> > know the length of the transfer Host is going to send. For Control OUT
>> > we know the length in wLength of
>> > Setup packet, hence I assumed there is no difference in programming
>> > model of Control IN and OUT.
>>
>> there is _no_ difference. It's just that it was agreed that for anything
>> other than control ep, the function drivers would take care of it. See
>> the uses of quirk_ep_out_aligned_size.

got it..:)

>
> btw, why are you reimplementing the driver when there's a perfectly good
> driver to use in mainline kernel ?

I am writing a bare metal driver and it didn't work without alignment
check mentioned above.

>
> --
> balbi

Thanks,
Sundeep.B.S.
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