From: Sultan Alsawaf sultan@kerneltoast.com

On all Dell laptops with panels and chipsets that support PSR (an esoteric power-saving mechanism), both PSR1 and PSR2 cause flickering and graphical glitches, sometimes to the point of making the laptop unusable. Many laptops don't support PSR so it isn't known if PSR works correctly on any consumer hardware right now. PSR was enabled by default in 5.0 for capable hardware, so this patch just restores the previous functionality of PSR being disabled by default.

More info is available on the freedesktop bug: https://gitlab.freedesktop.org/drm/intel/issues/425

Cc: stable@vger.kernel.org # 5.4.x, 5.5.x Signed-off-by: Sultan Alsawaf sultan@kerneltoast.com --- drivers/gpu/drm/i915/i915_params.c | 3 +-- drivers/gpu/drm/i915/i915_params.h | 2 +- 2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_params.c b/drivers/gpu/drm/i915/i915_params.c index 1dd1f3652795..0c4661fcf011 100644 --- a/drivers/gpu/drm/i915/i915_params.c +++ b/drivers/gpu/drm/i915/i915_params.c @@ -85,8 +85,7 @@ i915_param_named_unsafe(enable_hangcheck, bool, 0600,

i915_param_named_unsafe(enable_psr, int, 0600, "Enable PSR " - "(0=disabled, 1=enabled) " - "Default: -1 (use per-chip default)"); + "(-1=use per-chip default, 0=disabled [default], 1=enabled) ");

i915_param_named_unsafe(force_probe, charp, 0400, "Force probe the driver for specified devices. " diff --git a/drivers/gpu/drm/i915/i915_params.h b/drivers/gpu/drm/i915/i915_params.h index 31b88f297fbc..4a9a3df7d292 100644 --- a/drivers/gpu/drm/i915/i915_params.h +++ b/drivers/gpu/drm/i915/i915_params.h @@ -50,7 +50,7 @@ struct drm_printer; param(int, vbt_sdvo_panel_type, -1) \ param(int, enable_dc, -1) \ param(int, enable_fbc, -1) \ - param(int, enable_psr, -1) \ + param(int, enable_psr, 0) \ param(int, disable_power_well, -1) \ param(int, enable_ips, 1) \ param(int, invert_brightness, 0) \