Re: [PATCH 2/2] virtio: fix PCI config err handling

[Tiwei Bie <tiwei.bie@intel.com>]

On Tue, Aug 14, 2018 at 03:30:35PM +0100, Luca Boccassi wrote:
> From: Brian Russell <brussell@brocade.com>
> 
> In virtio_read_caps, rte_pci_read_config returns the number of bytes
> read from PCI config or < 0 on error.
> If less than the expected number of bytes are read then log the
> failure and return rather than carrying on with garbage.

Is this a fix or an improvement?
Or did you see anything broken without this patch?
If so, we may need a fixes line and Cc stable.

> 
> Signed-off-by: Brian Russell <brussell@brocade.com>
> ---
> 
> Follow-up from:
> http://mails.dpdk.org/archives/dev/2017-June/067278.html
> https://patches.dpdk.org/patch/25056/
> 
>  drivers/net/virtio/virtio_pci.c | 12 +++++++-----
>  1 file changed, 7 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/net/virtio/virtio_pci.c b/drivers/net/virtio/virtio_pci.c
> index 6bd22e54a6..a10698aed8 100644
> --- a/drivers/net/virtio/virtio_pci.c
> +++ b/drivers/net/virtio/virtio_pci.c
> @@ -567,16 +567,18 @@ virtio_read_caps(struct rte_pci_device *dev, struct virtio_hw *hw)
>  	}
>  
>  	ret = rte_pci_read_config(dev, &pos, 1, PCI_CAPABILITY_LIST);
> -	if (ret < 0) {
> -		PMD_INIT_LOG(DEBUG, "failed to read pci capability list");
> +	if (ret != 1) {
> +		PMD_INIT_LOG(DEBUG,
> +			     "failed to read pci capability list, ret %d", ret);
>  		return -1;
>  	}
>  
>  	while (pos) {
>  		ret = rte_pci_read_config(dev, &cap, sizeof(cap), pos);
> -		if (ret < 0) {
> -			PMD_INIT_LOG(ERR,
> -				"failed to read pci cap at pos: %x", pos);
> +		if (ret != sizeof(cap)) {
> +			PMD_INIT_LOG(DEBUG,

Why change the log level to DEBUG?

Thanks

> +				     "failed to read pci cap at pos: %x ret %d",
> +				     pos, ret);
>  			break;
>  		}
>  
> -- 
> 2.18.0
>