[dpdk-dev] FW: [PATCH v2] Fixes: 57f90f894588("net/virtio: reuse packed ring functions")

[Vipul Ashri <vipul.ashri@oracle.com>]

Hi Javin

FYI
http://patches.dpdk.org/patch/75476/
The mentioned fix you are trying to submit is already addressed and in review with Xia chenbo since 10th august.
Hope you can discard your patch as I have already sent the patch to dpdk community.

Regards
Vipul

-----Original Message-----
From: Xia, Chenbo [mailto:chenbo.xia@intel.com] 
Sent: Wednesday, 12 August, 2020 17:31
To: Vipul Ashri <vipul.ashri@oracle.com>; dev@dpdk.org
Cc: Edwin Leung <edwin.leung@oracle.com>
Subject: RE: [PATCH v2] Fixes: 57f90f894588("net/virtio: reuse packed ring functions")

Hi Vipul,

> -----Original Message-----
> From: Vipul Ashri <vipul.ashri@oracle.com>
> Sent: Wednesday, August 12, 2020 5:23 PM
> To: dev@dpdk.org
> Cc: Xia, Chenbo <chenbo.xia@intel.com>; vipul.ashri@oracle.com; 
> edwin.leung@oracle.com
> Subject: [PATCH v2] Fixes: 57f90f894588("net/virtio: reuse packed ring
> functions")
> 
> Problem - Standard Tx packets are not going out and found broken  due 
> to cleanup malfunctioning whereever below mentioned macro is  used.
> 
> RootCause - Here inside Macro 'ASSIGN_UNLESS_EQUAL(var, val)'
>  assignment to 'var' argument passed is always failing as assignment  
> done using 'var_' having local scope only.
> 
> Signed-off-by: Vipul Ashri <vipul.ashri@oracle.com>

I understand now. Your patch makes sense. But your commit title/msg is still wrong. An example commit message should be (you could use this):

net/virtio: fix wrong variable assignment in helper macro

Inside Macro ASSIGN_UNLESS_EQUAL(var, val), assignment to var is always failing as assignment done using var_ having local scope only. This leads to TX packets not going out and found broken due to cleanup malfunctioning. This patch fixes the wrong variable assignment.

Fixes: 57f90f894588("net/virtio: reuse packed ring functions")
Cc: stable@dpdk.org

Signed-off-by: Vipul Ashri <vipul.ashri@oracle.com>

> ---
>  drivers/net/virtio/virtqueue.h | 6 ++----
>  1 file changed, 2 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/net/virtio/virtqueue.h 
> b/drivers/net/virtio/virtqueue.h index 105a9c00c..20c95471e 100644
> --- a/drivers/net/virtio/virtqueue.h
> +++ b/drivers/net/virtio/virtqueue.h
> @@ -607,10 +607,8 @@ virtqueue_notify(struct virtqueue *vq)
> 
>  /* avoid write operation when necessary, to lessen cache issues */
>  #define ASSIGN_UNLESS_EQUAL(var, val) do {	\
> -	typeof(var) var_ = (var);		\
> -	typeof(val) val_ = (val);		\
> -	if ((var_) != (val_))			\
> -		(var_) = (val_);		\
> +	if ((var) != (val))			\
> +		(var) = (val);			\
>  } while (0)
> 
>  #define virtqueue_clear_net_hdr(hdr) do {		\
> --
> 2.28.0.windows.1