[dpdk-dev] [PATCH v2] e1000/base: fix multicast setting in VF

[Ferruh Yigit]

On 2/21/2017 9:33 AM, Yong Wang wrote:
> In function e1000_update_mc_addr_list_vf(), "msgbuf[0]" is used prior
> to initialization at "msgbuf[0] |= E1000_VF_SET_MULTICAST_OVERFLOW".
> And "msgbuf[0]" is overwritten at "msgbuf[0] = E1000_VF_SET_MULTICAST".
> Fix it by moving the second line prior to the first one that mentioned
> above.
> 
> ---
> v2:
> * According to Thomas's suggestion, modify the title.
> 
> Signed-off-by: Yong Wang <wang.yong19 at zte.com.cn>

It looks like this fix has a history:

- Defect introduces with initial version

- Fixed with: [1]
  06cf9be95ce1 ("lib: fix uninitialized value")

- Fix reverted with: [2]
  dffbaf7880a8 ("e1000: revert fix for multicast in VF")

- This patch applies same fix again.

Revert does not mention why it has been reverted, this is one of the
samples why commit log matters.

Since code is clearly wrong, I am for getting the fix, but it would be
nice to know why it has been reverted previously.


[1]
commit 06cf9be95ce16b363c4267d2d17e27c2706629ae
Author: Zijie Pan <zijie.pan at 6wind.com>
Date:   Thu Dec 6 15:36:51 2012 +0800

    lib: fix uninitialized value

    Fix warning "The left expression of the compound assignment
    is an uninitialized value".

    Signed-off-by: Zijie Pan <zijie.pan at 6wind.com>
    Acked-by: Ivan Boule <ivan.boule at 6wind.com>
    Acked-by: Adrien Mazarguil <adrien.mazarguil at 6wind.com>


[2]
commit dffbaf7880a8d753a4971971256d6c8b90e7ece1
Author: Intel <intel.com>
Date:   Fri Nov 8 03:00:00 2013 +0100

    e1000: revert fix for multicast in VF

    Revert fix from commit 06cf9be95ce16b363c4267d2d17e27c2706629ae.

    Signed-off-by: Intel