linux-kernel - [PATCH 0/1] drm/i915: Disable Panel Self Refresh (PSR) by default

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Message-Id: <20200330163006.4064-1-sultan@kerneltoast.com>
Date:   Mon, 30 Mar 2020 09:30:05 -0700
From:   Sultan Alsawaf <sultan@...neltoast.com>
To:     linux-kernel@...r.kernel.org
Cc:     Jani Nikula <jani.nikula@...ux.intel.com>,
        Joonas Lahtinen <joonas.lahtinen@...ux.intel.com>,
        Rodrigo Vivi <rodrigo.vivi@...el.com>,
        David Airlie <airlied@...ux.ie>,
        Daniel Vetter <daniel@...ll.ch>,
        intel-gfx@...ts.freedesktop.org, dri-devel@...ts.freedesktop.org,
        Sultan Alsawaf <sultan@...neltoast.com>
Subject: [PATCH 0/1] drm/i915: Disable Panel Self Refresh (PSR) by default

From: Sultan Alsawaf <sultan@...neltoast.com>

Hi,

Laptops which support an esoteric power-saving mechanism called Panel Self
Refresh (PSR) suffer from severe graphical corruption and flickering. Enabled by
default in 5.0, PSR causes graphical corruption to the point of unusability on
many Dell laptops made within the past few years, since they typically support
PSR. A bug was filed with Intel several months ago for this with more
information [1]. I suspect most of the community hasn't been affected by this
bug because ThinkPads and many other laptops I checked didn't support PSR. As of
writing, the issues I observed with PSR are neither fully fixed in Intel's
drm-tip branch nor in 5.6. Disabling PSR by default brings us safely back to
pre-5.0 behavior, remedying the glitches. Also, Ubuntu now ships with PSR
disabled by default in its affected kernels, so there is distro support behind
this change.

Thanks,
Sultan

[1] https://gitlab.freedesktop.org/drm/intel/issues/425

Sultan Alsawaf (1):
  drm/i915: Disable Panel Self Refresh (PSR) by default

 drivers/gpu/drm/i915/i915_params.c | 3 +--
 drivers/gpu/drm/i915/i915_params.h | 2 +-
 2 files changed, 2 insertions(+), 3 deletions(-)

-- 
2.26.0