Re: [PATCH net-next] net: ethernet: mlx4: Avoid assigning a value to ring_cons but not used it anymore in mlx4_en_xmit()

From: David Miller
Date: Sun Sep 13 2020 - 17:33:18 EST

From: Tariq Toukan <ttoukan.linux@xxxxxxxxx>
Date: Sun, 13 Sep 2020 13:12:05 +0300

> On 9/13/2020 4:22 AM, David Miller wrote:
>> From: Luo Jiaxing <luojiaxing@xxxxxxxxxx>
>> Date: Sat, 12 Sep 2020 16:08:15 +0800
>>> We found a set but not used variable 'ring_cons' in mlx4_en_xmit(), it
>>> will
>>> cause a warning when build the kernel. And after checking the commit
>>> record
>>> of this function, we found that it was introduced by a previous patch.
>>> So, We delete this redundant assignment code.
>>> Fixes: 488a9b48e398 ("net/mlx4_en: Wake TX queues only when there's
>>> enough room")
>>> Signed-off-by: Luo Jiaxing <luojiaxing@xxxxxxxxxx>
>> Looks good, applied, thanks.
> Hi Luo,
> I didn't get a chance to review it during the weekend.

Tariq, what are you even commenting on? Are you responding to this patch
which removes a %100 obviously unused variable set, or on the commit
mentioned in the Fixes: tag?

> The ring_cons local variable is used in line 903:

He is removing an assignment to ring_cons much later in the function
and therefore has no effect on this line.

> 1. Your patch causes a degradation to the case when MLX4_EN_PERF_STAT
> is defined.

This is not true, see above.