Hello Paul,
On Mon, 2022-02-07 at 16:38 -0500, Lyude Paul wrote:
As we've unfortunately started to come to expect from PSR on Intel platforms, PSR2 selective fetch is not at all ready to be enabled on Tigerlake as it results in severe flickering issues - at least on this ThinkPad X1 Carbon 9th generation. The easiest way I've found of reproducing these issues is to just move the cursor around the left border of the screen (suspicious…).
Sorry to hear you have this bad experience with i915 PSR2 selective fetch support. There is already some discussion about these problems and possible root causes here:
https://gitlab.freedesktop.org/drm/intel/-/issues/4951
I have Dell XPS 13 7390 which has panel supporting PSR2. Luckily I'm not facing these problems with it.
So, fix people's displays again and turn PSR2 selective fetch off for all steppings of Tigerlake. This can be re-enabled again if someone from Intel finds the time to fix this functionality on OEM machines.
Signed-off-by: Lyude Paul lyude@redhat.com Fixes: 7f6002e58025 ("drm/i915/display: Enable PSR2 selective fetch by default") Cc: Gwan-gyeong Mun gwan-gyeong.mun@intel.com Cc: Ville Syrjälä ville.syrjala@linux.intel.com Cc: José Roberto de Souza jose.souza@intel.com Cc: Jani Nikula jani.nikula@linux.intel.com Cc: Rodrigo Vivi rodrigo.vivi@intel.com Cc: intel-gfx@lists.freedesktop.org Cc: stable@vger.kernel.org # v5.16+
drivers/gpu/drm/i915/display/intel_psr.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/i915/display/intel_psr.c b/drivers/gpu/drm/i915/display/intel_psr.c index a1a663f362e7..25c16abcd9cd 100644 --- a/drivers/gpu/drm/i915/display/intel_psr.c +++ b/drivers/gpu/drm/i915/display/intel_psr.c @@ -737,10 +737,14 @@ static bool intel_psr2_sel_fetch_config_valid(struct intel_dp *intel_dp, return false; }
- /* Wa_14010254185 Wa_14010103792 */
- if (IS_TGL_DISPLAY_STEP(dev_priv, STEP_A0, STEP_C0)) {
- /*
* There's two things stopping this from being enabled on TGL:* For steps A0-C0: workarounds Wa_14010254185 Wa_14010103792are missing
* For all steps: PSR2 selective fetch causes screen flickering*/- if (IS_TIGERLAKE(dev_priv)) { drm_dbg_kms(&dev_priv->drm,
"PSR2 sel fetch not enabled, missing theimplementation of WAs\n");
"PSR2 sel fetch not enabled, currentlybroken on TGL\n"); return false; }
BR,
Jouni Högander