On Tue, 02 Feb 2021 00:18:09 +0100,
Anton Yakovlev wrote:
> >> +/**
> >> + * virtsnd_reset_fn() - Kernel worker's function to reset the device.
> >> + * @work: Reset device work.
> >> + *
> >> + * Context: Process context.
> >> + */
> >> +static void virtsnd_reset_fn(struct work_struct *work)
> >> +{
> >> + struct virtio_snd *snd =
> >> + container_of(work, struct virtio_snd, reset_work);
> >> + struct virtio_device *vdev = snd->vdev;
> >> + struct device *dev = &vdev->dev;
> >> + int rc;
> >> +
> >> + dev_info(dev, "sound device needs reset\n");
> >> +
> >> + /*
> >> + * It seems that the only way to properly reset the device is to
> >> remove
> >> + * and re-create the ALSA sound card device.
> >> + *
> >> + * Also resetting the device involves a number of steps with
> >> setting the
> >> + * status bits described in the virtio specification. And the
> >> easiest
> >> + * way to get everything right is to use the virtio bus interface.
> >> + */
> >> + rc = dev->bus->remove(dev);
> >> + if (rc)
> >> + dev_warn(dev, "bus->remove() failed: %d", rc);
> >> +
> >> + rc = dev->bus->probe(dev);
> >> + if (rc)
> >> + dev_err(dev, "bus->probe() failed: %d", rc);
> >
> > This looks very suspicious to me. Wondering what ALSA maintainers
> will say
> > to this.
>
> I'm also wondering what the virtio people have to say. This part is a
> purely virtio specific thing. And since none of the existing virtio
> drivers processes the request to reset the device, it is not clear what
> is the best way to proceed here. For this reason, the most
> straightforward and simple solution was chosen.
What is this "reset" actually supposed to do? Reconfguring
everything, or changing only certain parameters, devices, whatever?
thanks,
Takashi
