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Re: [PATCH v2] usb: gadget: f_midi: Add checking if it need align buffer's size to an ep's maxpacketsize

From Baolin Wang <baolin.wang@linaro.org>
Newsgroups linux.kernel
Subject Re: [PATCH v2] usb: gadget: f_midi: Add checking if it need align buffer's size to an ep's maxpacketsize
Date 2016-07-12 07:20 +0200
Message-ID <rTYgW-vb-5@gated-at.bofh.it> (permalink)
References <rTzBU-14B-11@gated-at.bofh.it> <rTHJ8-6qA-23@gated-at.bofh.it>
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On 11 July 2016 at 19:38, Michal Nazarewicz <mina86@mina86.com> wrote:
> On Mon, Jul 11 2016, Baolin Wang wrote:
>> Some gadget device (such as dwc3 gadget) requires quirk_ep_out_aligned_size
>> attribute, which means it need to align the request buffer's size to an ep's
>> maxpacketsize.
>>
>> Thus we add usb_ep_align_maybe() function to check if it is need to align
>> the request buffer's size to an ep's maxpacketsize.
>>
>> Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
>> Acked-by: Michal Nazarewicz <mina86@mina86.com>
>> ---
>> Changelog since v1:
>>  - Remove the in_ep modification.
>>  - Remove max_t() function.
>>
>>  drivers/usb/gadget/function/f_midi.c |   12 ++++++++----
>>  1 file changed, 8 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/usb/gadget/function/f_midi.c b/drivers/usb/gadget/function/f_midi.c
>> index 58fc199..59f6278 100644
>> --- a/drivers/usb/gadget/function/f_midi.c
>> +++ b/drivers/usb/gadget/function/f_midi.c
>> @@ -359,10 +359,14 @@ static int f_midi_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
>>
>>       /* allocate a bunch of read buffers and queue them all at once. */
>>       for (i = 0; i < midi->qlen && err == 0; i++) {
>> -             struct usb_request *req =
>> -                     midi_alloc_ep_req(midi->out_ep,
>> -                             max_t(unsigned, midi->buflen,
>> -                                     bulk_out_desc.wMaxPacketSize));
>> +             struct usb_request *req;
>> +             unsigned length;
>> +
>> +             length = midi->buflen < bulk_out_desc.wMaxPacketSize
>> +                     ? bulk_out_desc.wMaxPacketSize
>> +                     : usb_ep_align_maybe(midi->gadget, midi->out_ep,
>> +                                          midi->buflen);
>
> As pointed out by Felipe, the packet does not need to be wMaxPacketSize
> so this can simply be:

OK. Thanks.

>
>> +             length = usb_ep_align_maybe(midi->gadget, midi->out_ep,
>> +                                         midi->buflen);
>
>> +             req = midi_alloc_ep_req(midi->out_ep, length);
>>               if (req == NULL)
>>                       return -ENOMEM;
>>
>> --
>> 1.7.9.5
>>
>
> --
> Best regards
> ミハウ “𝓶𝓲𝓷𝓪86” ナザレヴイツ
> «If at first you don’t succeed, give up skydiving»



-- 
Baolin.wang
Best Regards

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[PATCH v2] usb: gadget: f_midi: Add checking if it need align buffer's size to an ep's maxpacketsize Baolin Wang <baolin.wang@linaro.org> - 2016-07-11 05:00 +0200
  Re: [PATCH v2] usb: gadget: f_midi: Add checking if it need align buffer's size to an ep's maxpacketsize Michal Nazarewicz <mina86@mina86.com> - 2016-07-11 13:40 +0200
    Re: [PATCH v2] usb: gadget: f_midi: Add checking if it need align  buffer's size to an ep's maxpacketsize Baolin Wang <baolin.wang@linaro.org> - 2016-07-12 07:20 +0200

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