Re: [dpdk-dev] [PATCH v1] net/virtio: wait device ready during reset

["Xueming(Steven) Li" <xuemingl@nvidia.com>]

On Wed, 2021-09-15 at 12:27 +0300, Andrew Rybchenko wrote:
> On 9/15/21 12:21 PM, Xueming Li wrote:
> > According to virtio spec, the device MUST reset when 0 is written to
> > device_status, and present 0 in device_status once reset is done.
> > 
> > This patch waits status value to be 0 during reset operation, if
> > timeout in 3 seconds, log and continue.
> 
> I have no strong opinion on timeout.
> 
> > 
> > Signed-off-by: Xueming Li <xuemingl@nvidia.com>
> > Cc: Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>
> > ---
> >  drivers/net/virtio/virtio.c | 15 +++++++++++++--
> >  1 file changed, 13 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/net/virtio/virtio.c b/drivers/net/virtio/virtio.c
> > index 7e1e77797f..f865b27b65 100644
> > --- a/drivers/net/virtio/virtio.c
> > +++ b/drivers/net/virtio/virtio.c
> > @@ -3,7 +3,10 @@
> >   * Copyright(c) 2020 Red Hat, Inc.
> >   */
> >  
> > +#include <unistd.h>
> > +
> >  #include "virtio.h"
> > +#include "virtio_logs.h"
> >  
> >  uint64_t
> >  virtio_negotiate_features(struct virtio_hw *hw, uint64_t host_features)
> > @@ -38,9 +41,17 @@ virtio_write_dev_config(struct virtio_hw *hw, size_t offset,
> >  void
> >  virtio_reset(struct virtio_hw *hw)
> >  {
> > +	uint32_t retry = 0;
> > +
> >  	VIRTIO_OPS(hw)->set_status(hw, VIRTIO_CONFIG_STATUS_RESET);
> > -	/* flush status write */
> > -	VIRTIO_OPS(hw)->get_status(hw);
> > +	/* Flush status write and wait device ready max 3 seconds. */
> > +	while (VIRTIO_OPS(hw)->get_status(hw) != VIRTIO_CONFIG_STATUS_RESET) {
> > +		if (retry++ > 3000) {
> > +			PMD_INIT_LOG(WARNING, "device reset timeout");
> 
> I think it would be very useful to log ethdev port ID here.

Good suggesiton, v2 sent.

> 
> > +			break;
> > +		}
> > +		usleep(1000L);
> > +	}
> >  }
> >  
> >  void
> > 
>