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From: Felipe Balbi <balbi@ti.com>
To: Clemens Ladisch <clemens@ladisch.de>,
	Felipe Tonello <eu@felipetonello.com>,
	USB list <linux-usb@vger.kernel.org>
Cc: Kernel development list <linux-kernel@vger.kernel.org>,
	Peter Chen <Peter.Chen@freescale.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Subject: Re: [PATCH v3 1/4] usb: gadget: f_midi: free usb request when done
Date: Fri, 9 Oct 2015 15:55:51 -0500	[thread overview]
Message-ID: <871td3vk14.fsf@saruman.tx.rr.com> (raw)
In-Reply-To: <56178799.9000409@ladisch.de>

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Hi,

Clemens Ladisch <clemens@ladisch.de> writes:
> Felipe Tonello wrote:
>> req->actual == req->length means that there is no data left to enqueue,
>
> This condition is not checked in the patch.
>
>> so free the request.
>>
>> Signed-off-by: Felipe F. Tonello <eu@felipetonello.com>
>> ---
>>  drivers/usb/gadget/function/f_midi.c | 5 ++---
>>  1 file changed, 2 insertions(+), 3 deletions(-)
>> diff --git a/drivers/usb/gadget/function/f_midi.c b/drivers/usb/gadget/function/f_midi.c
>> index edb84ca..93212ca 100644
>> --- a/drivers/usb/gadget/function/f_midi.c
>> +++ b/drivers/usb/gadget/function/f_midi.c
>> @@ -256,9 +256,8 @@ f_midi_complete(struct usb_ep *ep, struct usb_request *req)
>>  			/* We received stuff. req is queued again, below */
>>  			f_midi_handle_out_data(ep, req);
>>  		} else if (ep == midi->in_ep) {
>> -			/* Our transmit completed. See if there's more to go.
>> -			 * f_midi_transmit eats req, don't queue it again. */
>> -			f_midi_transmit(midi, req);
>> +			/* Our transmit completed. Don't queue it again. */
>> +			free_ep_req(ep, req);
>>  			return;
>>  		}
>>  		break;
>
> The ALSA framework will give you a notification _once_.  If the
> resulting data is larger than midi->buflen, then you have to continue
> sending packets.  This is exactly what the call to f_midi_transmit()
> does.
>
> (To decrease latency, it might be a good idea to queue multiple requests,
> but you wouldn't want to continue piling up requests if the host isn't
> listening.  sound/usb/midi.c just allocates a fixed number of requests,
> and always reuses them.)

so, should I drop this series from my TODO queue ?

-- 
balbi

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  reply	other threads:[~2015-10-09 20:56 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-09-29 12:01 [PATCH v3 0/4] USB MIDI Gadget bug fixes and improvements Felipe F. Tonello
2015-09-29 12:01 ` [PATCH v3 1/4] usb: gadget: f_midi: free usb request when done Felipe F. Tonello
2015-09-29 12:01 ` [PATCH v3 2/4] usb: gadget: f_midi: free request when usb_ep_queue fails Felipe F. Tonello
2015-09-29 12:01 ` [PATCH v3 3/4] usb: gadget: f_midi: Transmit data only when IN ep is enabled Felipe F. Tonello
2015-09-29 12:01 ` [PATCH v3 4/4] usb: gadget: f_midi: remove duplicated code Felipe F. Tonello
2015-10-08  8:36 ` [PATCH v3 0/4] USB MIDI Gadget bug fixes and improvements Felipe Tonello
2015-10-09  9:23   ` [PATCH v3 1/4] usb: gadget: f_midi: free usb request when done Clemens Ladisch
2015-10-09 20:55     ` Felipe Balbi [this message]
2015-10-11 19:08       ` Clemens Ladisch
2015-10-12 10:11         ` Felipe Tonello
2015-10-12  9:46     ` Felipe Tonello
2015-10-12 10:16       ` Clemens Ladisch
2015-10-12 11:58         ` Felipe Tonello
2015-10-12 12:10           ` Clemens Ladisch

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