> On (Fri) 02 Nov 2012 [09:52:08], Rusty Russell wrote:
> > Amit Shah <amit.shah@xxxxxxxxxx> writes:
> > > On (Tue) 23 Oct 2012 [12:17:49], Rusty Russell wrote:
> > >> sjur.brandeland@xxxxxxxxxxxxxx writes:
> > >> > From: Sjur Brændeland <sjur.brandeland@xxxxxxxxxxxxxx>
> > >
> > >> > @@ -1415,7 +1524,16 @@ static void remove_port_data(struct port
> *port)
> > >> >
> > >> > /* Remove buffers we queued up for the Host to send us data in. */
> > >> > while ((buf = virtqueue_detach_unused_buf(port->in_vq)))
> > >> > - free_buf(buf);
> > >> > + free_buf(buf, true);
> > >> > +
> > >> > + /*
> > >> > + * Remove buffers from out queue for rproc-serial. We
> cannot afford
> > >> > + * to leak any DMA mem, so reclaim this memory even if this
> might be
> > >> > + * racy for the remote processor.
> > >> > + */
> > >> > + if (is_rproc_serial(port->portdev->vdev))
> > >> > + while ((buf = virtqueue_detach_unused_buf(port-
> >out_vq)))
> > >> > + free_buf(buf, true);
> > >> > }
> > >>
> > >> This seems wrong; either this is needed even if !is_rproc_serial(), or
> > >> it's not necessary as the out_vq is empty.
> > >>
> > >> Every path I can see has the device reset (in which case the queues
> > >> should not be active), or we got a VIRTIO_CONSOLE_PORT_REMOVE
> event (in
> > >> which case, the same).
> > >>
> > >> I think we can have non-blocking writes which could leave buffers in
> > >> out_vq: Amit?
> > >
> > > Those get 'reclaimed' just above this hunk:
> > >
> > >
> > > static void remove_port_data(struct port *port)
> > > {
> > > struct port_buffer *buf;
> > >
> > > /* Remove unused data this port might have received. */
> > > discard_port_data(port);
> > >
> > > reclaim_consumed_buffers(port);
> > >
> > > /* Remove buffers we queued up for the Host to send us data in. */
> > > while ((buf = virtqueue_detach_unused_buf(port->in_vq)))
> > > free_buf(buf, true);
> >
> > No, that's pending input buffers, not output buffers.
>
> You're right. Nice catch.
>
> Sjur, can you remove the WARN_ON in your latest series, even generic
> ports may have buffers in the outq.
Sure, I can respin the patch and remove the WARN_ON().
> It'll also need to be done in the port_fops_release() function. Let
> me know if you prefer I send a patch instead.
I can have a go at this, as I have to respin the patch anyway.
Thanks,
Sjur
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