[alsa-devel] [PATCH v2] ALSA: snd-usb-audio: set the timeout for usb control set messages to 5000 ms

[Daniel Schürmann]

Hi Torstein, Hi Daniel

Thank you for your hint.

Just noticed that the get timeout is also set to 5000 ms even if the USB 2
spec only allows 500 ms.

Do you think it is also a good idea to adopt the 5000 ms get timout for
snd-usb-audio?

Kind regards,

Daniel

/*
 * timeouts, in milliseconds, used for sending/receiving control messages
 * they typically complete within a few frames (msec) after they're issued
 * USB identifies 5 second timeouts, maybe more in a few cases, and a few
 * slow devices (like some MGE Ellipse UPSes) actually push that limit.
 */
#define USB_CTRL_GET_TIMEOUT    5000
#define USB_CTRL_SET_TIMEOUT    5000






2013/4/20 Torstein Hegge <hegge at resisty.net>

> On Sat, Apr 20, 2013 at 20:58:56 +0200, Daniel Schürmann wrote:
> > Thank you Daniel for review.
> > Here is an updated version of the patch against
> > https://git.kernel.org/cgit/linux/kernel/git/tiwai/sound.git/
> > 581cbef46ae60073252208fc1f26dd1044f6e215
> >
> > Set the timeout for USB control set messages according to the USB 2 spec
> > §9.2.6.4 to 5000 ms.
> > To avoid new issues, the get timeout is unchanged at 1000 ms, though it
> > is 500 ms in the spec.
> > This patch is required to run the Hercules RMX2 which needs a timeout >
> > 1240 ms
> >
> > Signed-off-by: Daniel Schürmann <daschuer at mixxx.org>
> > ---
> > diff --git a/sound/usb/helper.c b/sound/usb/helper.c
> > index c1db28f..c1caae4 100644
> > --- a/sound/usb/helper.c
> > +++ b/sound/usb/helper.c
> > @@ -23,6 +23,11 @@
> >  #include "helper.h"
> >  #include "quirks.h"
> >
> > +/* Value from 9.2.6.4 USB 2 spec */
> > +#define USB_MSG_SET_TIMEOUT 5000
>
> There is an USB_CTRL_SET_TIMEOUT of 5000 ms defined in
> include/linux/usb.h, which is used by other callers of
> usb_control_msg(). And linux/usb.h is already included by helper.c.
>
> > +/* Value from spec is 500 but we pick 1000 for legacy reasons */
> > +#define USB_MSG_GET_TIMEOUT 1000
> > +
> >  /*
> >   * combine bytes and get an integer value
> >   */
> > @@ -86,14 +91,19 @@ int snd_usb_ctl_msg(struct usb_device *dev, unsigned
> > int pipe, __u8 request,
> >  {
> >      int err;
> >      void *buf = NULL;
> > +    int timeout;
> >
> >      if (size > 0) {
> >          buf = kmemdup(data, size, GFP_KERNEL);
> >          if (!buf)
> >              return -ENOMEM;
> >      }
> > +    if (requesttype & USB_DIR_IN)
> > +        timeout = USB_MSG_GET_TIMEOUT;
> > +    else
> > +        timeout = USB_MSG_SET_TIMEOUT;
> >      err = usb_control_msg(dev, pipe, request, requesttype,
> > -                  value, index, buf, size, 1000);
> > +                  value, index, buf, size, timeout);
> >      if (size > 0) {
> >          memcpy(data, buf, size);
> >          kfree(buf);
>