* [PATCH v2 2/3] usb: gadget: f_midi: free usb request when done
@ 2015-09-23 12:01 Felipe F. Tonello
2015-09-23 13:12 ` Sergei Shtylyov
2015-09-24 1:38 ` Peter Chen
0 siblings, 2 replies; 5+ messages in thread
From: Felipe F. Tonello @ 2015-09-23 12:01 UTC (permalink / raw)
To: linux-usb
Cc: linux-kernel, Peter Chen, Greg Kroah-Hartman, Felipe Balbi,
Andrzej Pietrasiewicz, Felipe F. Tonello
req->actual == req->length means that there is no data left to enqueue,
so free the request.
Signed-off-by: Felipe F. Tonello <eu@felipetonello.com>
---
Changes in v2:
* Re enqueue not fully completed requests, instead of read ALSA buffers.
drivers/usb/gadget/function/f_midi.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/drivers/usb/gadget/function/f_midi.c b/drivers/usb/gadget/function/f_midi.c
index edb84ca..62356cf 100644
--- a/drivers/usb/gadget/function/f_midi.c
+++ b/drivers/usb/gadget/function/f_midi.c
@@ -256,10 +256,12 @@ 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);
- return;
+ /* Our transmit completed. If there is no more to go,
+ don't queue it again. */
+ if (req->actual == req->length) {
+ free_ep_req(ep, req);
+ return;
+ }
}
break;
--
2.1.4
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH v2 2/3] usb: gadget: f_midi: free usb request when done
2015-09-23 12:01 [PATCH v2 2/3] usb: gadget: f_midi: free usb request when done Felipe F. Tonello
@ 2015-09-23 13:12 ` Sergei Shtylyov
2015-09-24 1:38 ` Peter Chen
1 sibling, 0 replies; 5+ messages in thread
From: Sergei Shtylyov @ 2015-09-23 13:12 UTC (permalink / raw)
To: Felipe F. Tonello, linux-usb
Cc: linux-kernel, Peter Chen, Greg Kroah-Hartman, Felipe Balbi,
Andrzej Pietrasiewicz
Hello.
On 9/23/2015 3:01 PM, Felipe F. Tonello wrote:
> req->actual == req->length means that there is no data left to enqueue,
> so free the request.
>
> Signed-off-by: Felipe F. Tonello <eu@felipetonello.com>
> ---
>
> Changes in v2:
> * Re enqueue not fully completed requests, instead of read ALSA buffers.
>
> drivers/usb/gadget/function/f_midi.c | 10 ++++++----
> 1 file changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/usb/gadget/function/f_midi.c b/drivers/usb/gadget/function/f_midi.c
> index edb84ca..62356cf 100644
> --- a/drivers/usb/gadget/function/f_midi.c
> +++ b/drivers/usb/gadget/function/f_midi.c
> @@ -256,10 +256,12 @@ 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);
> - return;
> + /* Our transmit completed. If there is no more to go,
> + don't queue it again. */
The preferred multi-line comment style is this:
/*
* bla
* bla
*/
MBR, Sergei
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v2 2/3] usb: gadget: f_midi: free usb request when done
2015-09-23 12:01 [PATCH v2 2/3] usb: gadget: f_midi: free usb request when done Felipe F. Tonello
2015-09-23 13:12 ` Sergei Shtylyov
@ 2015-09-24 1:38 ` Peter Chen
2015-09-24 6:44 ` Clemens Ladisch
2015-09-25 9:22 ` Felipe Tonello
1 sibling, 2 replies; 5+ messages in thread
From: Peter Chen @ 2015-09-24 1:38 UTC (permalink / raw)
To: Felipe F. Tonello
Cc: linux-usb, linux-kernel, Greg Kroah-Hartman, Felipe Balbi,
Andrzej Pietrasiewicz
On Wed, Sep 23, 2015 at 01:01:44PM +0100, Felipe F. Tonello wrote:
> req->actual == req->length means that there is no data left to enqueue,
> so free the request.
>
> Signed-off-by: Felipe F. Tonello <eu@felipetonello.com>
> ---
>
> Changes in v2:
> * Re enqueue not fully completed requests, instead of read ALSA buffers.
>
> drivers/usb/gadget/function/f_midi.c | 10 ++++++----
> 1 file changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/usb/gadget/function/f_midi.c b/drivers/usb/gadget/function/f_midi.c
> index edb84ca..62356cf 100644
> --- a/drivers/usb/gadget/function/f_midi.c
> +++ b/drivers/usb/gadget/function/f_midi.c
> @@ -256,10 +256,12 @@ 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);
> - return;
> + /* Our transmit completed. If there is no more to go,
> + don't queue it again. */
> + if (req->actual == req->length) {
> + free_ep_req(ep, req);
> + return;
> + }
I find f_midi_transmit will judge if there are more data, if without
data, it will free the request.
Besides, does one trigger only do one transfer? Sorry, I can't make my
aplaymidi to receive data, probably due to hardware without midi
support?
root@imx6qpsabreauto:~# aplaymidi
ALSA lib
/var/lib/jenkins/workspace/fido-3.14.28-X11-consolidated_new/temp_build_dir/build_all/tmp/work/cortexa9hf-vfp-neon-mx6qdl-poky-linux-gnueabi/alsa-lib/1.0.28-r0/alsa-lib-1.0.28/src/seq/seq_hw.c:457:(snd_seq_hw_open)
open /dev/snd/seq failed: No such file or directory
Cannot open sequencer - No such file or directory
--
Best Regards,
Peter Chen
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v2 2/3] usb: gadget: f_midi: free usb request when done
2015-09-24 1:38 ` Peter Chen
@ 2015-09-24 6:44 ` Clemens Ladisch
2015-09-25 9:22 ` Felipe Tonello
1 sibling, 0 replies; 5+ messages in thread
From: Clemens Ladisch @ 2015-09-24 6:44 UTC (permalink / raw)
To: Peter Chen; +Cc: linux-usb, linux-kernel
Peter Chen wrote:
> I can't make my aplaymidi to receive data
> # aplaymidi
> open /dev/snd/seq failed: No such file or directory
modprobe snd-seq
There are mechanisms to load it automatically, but your embedded system
might not bother about any of them. Or CONFIG_SND_SEQUENCER isn't
enabled at all.
In any case, raw MIDI (with the amidi tool) should work.
Regards,
Clemens
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v2 2/3] usb: gadget: f_midi: free usb request when done
2015-09-24 1:38 ` Peter Chen
2015-09-24 6:44 ` Clemens Ladisch
@ 2015-09-25 9:22 ` Felipe Tonello
1 sibling, 0 replies; 5+ messages in thread
From: Felipe Tonello @ 2015-09-25 9:22 UTC (permalink / raw)
To: Peter Chen
Cc: USB list, Kernel development list, Greg Kroah-Hartman,
Felipe Balbi, Andrzej Pietrasiewicz
Hi Peter,
On Thu, Sep 24, 2015 at 2:38 AM, Peter Chen <peter.chen@freescale.com> wrote:
> On Wed, Sep 23, 2015 at 01:01:44PM +0100, Felipe F. Tonello wrote:
>> req->actual == req->length means that there is no data left to enqueue,
>> so free the request.
>>
>> Signed-off-by: Felipe F. Tonello <eu@felipetonello.com>
>> ---
>>
>> Changes in v2:
>> * Re enqueue not fully completed requests, instead of read ALSA buffers.
>>
>> drivers/usb/gadget/function/f_midi.c | 10 ++++++----
>> 1 file changed, 6 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/usb/gadget/function/f_midi.c b/drivers/usb/gadget/function/f_midi.c
>> index edb84ca..62356cf 100644
>> --- a/drivers/usb/gadget/function/f_midi.c
>> +++ b/drivers/usb/gadget/function/f_midi.c
>> @@ -256,10 +256,12 @@ 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);
>> - return;
>> + /* Our transmit completed. If there is no more to go,
>> + don't queue it again. */
>> + if (req->actual == req->length) {
>> + free_ep_req(ep, req);
>> + return;
>> + }
>
> I find f_midi_transmit will judge if there are more data, if without
> data, it will free the request.
No. Transmit is called when ALSA trigger is called (whenever
snd_*_read() snd_*_write() is called).
The current code is not crashing anything, but I believe it is just
wrong. It can cause potential problems in future if one is not careful
when doing changes to it.
I would like to send a v3 with free_ep_req().
Felipe
>
> Besides, does one trigger only do one transfer? Sorry, I can't make my
> aplaymidi to receive data, probably due to hardware without midi
> support?
>
> root@imx6qpsabreauto:~# aplaymidi
> ALSA lib
> /var/lib/jenkins/workspace/fido-3.14.28-X11-consolidated_new/temp_build_dir/build_all/tmp/work/cortexa9hf-vfp-neon-mx6qdl-poky-linux-gnueabi/alsa-lib/1.0.28-r0/alsa-lib-1.0.28/src/seq/seq_hw.c:457:(snd_seq_hw_open)
> open /dev/snd/seq failed: No such file or directory
> Cannot open sequencer - No such file or directory
>
> --
>
> Best Regards,
> Peter Chen
^ permalink raw reply [flat|nested] 5+ messages in thread
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2015-09-23 12:01 [PATCH v2 2/3] usb: gadget: f_midi: free usb request when done Felipe F. Tonello
2015-09-23 13:12 ` Sergei Shtylyov
2015-09-24 1:38 ` Peter Chen
2015-09-24 6:44 ` Clemens Ladisch
2015-09-25 9:22 ` Felipe Tonello
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