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

From: Baolin Wang
Date: Tue Jul 12 2016 - 01:14:15 EST


On 11 July 2016 at 19:38, Michal Nazarewicz <mina86@xxxxxxxxxx> 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@xxxxxxxxxx>
>> Acked-by: Michal Nazarewicz <mina86@xxxxxxxxxx>
>> ---
>> 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
> ããã âðððð86â ãããããã
> ÂIf at first you donât succeed, give up skydivingÂ



--
Baolin.wang
Best Regards