On (Tue) 23 Oct 2012 [12:17:49], Rusty Russell wrote:
> sjur.brandel...@stericsson.com writes:
> > From: Sjur Brændeland <sjur.brandel...@stericsson.com>

> > @@ -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);

  ...




> >  static void __exit fini(void)
> >  {
> > +   reclaim_dma_bufs();
> 
> Hmm, you didn't protect it here anyway...
> 
> Cheers,
> Rusty.

                Amit
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