[Intel-gfx] regression bisected: display sync drops after 7221fc33

[Ville Syrjälä]

On Mon, Jan 25, 2016 at 09:35:26AM -0700, dann frazier wrote:
> I've got a Lenovo T410 w/ an external display (DisplayPort<->HDMI). After
> upgrading from a 4.2 kernel to a 4.3, I started hitting an issue where
> the display thinks it has lost input for a few moments. Oddly, it
> usually happens when I start typing in a terminal after a short period
> of inactivity.
> 
> I see no OS-side symptoms - there are no new messages in dmesg/syslog/Xorg
> log, etc.

Any fifo underrun reports in dmesg in general?

> I reproduced with latest Linus master (@ 3e1e21c7b), and then
> bisected down to the following commit:
> 
> commit 7221fc333dbe1743a3dff155b03527fda90d4ec1
> Author: Matt Roper <matthew.d.roper at intel.com>
> Date:   Thu Sep 24 15:53:08 2015 -0700
> 
>     drm/i915: Eliminate usage of pipe_wm_parameters from ILK-style WM (v2)

That's not in 4.3.

As far as currentl Linus tree goes, you may want to try these:
http://patchwork.freedesktop.org/patch/msgid/1452776015-22076-2-git-send-email-ville.syrjala@linux.intel.com
http://patchwork.freedesktop.org/patch/msgid/1452776015-22076-1-git-send-email-ville.syrjala@linux.intel.com

-- 
Ville Syrjälä
Intel OTC