Re: [PATCH AUTOSEL for 4.9 36/56] drm/i915: Fix the level 0 max_wm hack on VLV/CHV

[Ville Syrjälä]

On Wed, Nov 15, 2017 at 04:44:54PM +0000, alexander.levin@xxxxxxxxxxx wrote:
> On Wed, Nov 15, 2017 at 01:08:05PM +0200, Ville Syrjälä wrote:
> >On Wed, Nov 15, 2017 at 02:45:43AM +0000, alexander.levin@xxxxxxxxxxx wrote:
> >> From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
> >>
> >> [ Upstream commit 1be4d3793d5a93daddcd9be657c429b38ad750a3 ]
> >>
> >> The watermark should never exceed the FIFO size, so we need to
> >> check against the current FIFO size instead of the theoretical
> >> maximum when we clamp the level 0 watermark.
> >>
> >> Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
> >> Link: https://urldefense.proofpoint.com/v2/url?u=http-3A__patchwork.freedesktop.org_patch_msgid_1480354637-2D14209-2D4-2Dgit-2Dsend-2Demail-2Dville.syrjala-40linux.intel.com&d=DwIDAw&c=udBTRvFvXC5Dhqg7UHpJlPps3mZ3LRxpb6__0PomBTQ&r=bUtaaC9mlBij4OjEG_D-KPul_335azYzfC4Rjgomobo&m=iuPtUar-VEGbH1jmVH_UTr4C02X8fmjHUfNYix-Yc0Y&s=ha_F0zP3A1Aztp5S5e6_bqdhiuuPXhn0dRWQ58vv3Is&e=
> >> Reviewed-by: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx>
> >> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
> >
> >Why are these patches being proposed for stable? They're not straight up
> >fixes for known issues, and there's always a chance that something will
> >break. Who is doing the qa on this?
> 
> Hi Ville,
> 
> They were selected automatically as part of a new process we're trying
> out. If you disagree with the selection I'd be happy to drop it.

How does that automatic process decide that a patch should be backported?

drm and i915 are very fast moving targets so unintended side effects from
backported patches is a real possibility. So I would recommend against
backporting anything that isn't fixing a real issue affecting users. We
do try to add the cc:stable to such patches.

-- 
Ville Syrjälä
Intel OTC