On Tue, 16 Jan 2024, Ville Syrjala ville.syrjala@linux.intel.com wrote:

From: Ville Syrjälä ville.syrjala@linux.intel.com

This reverts commit 88b065943cb583e890324d618e8d4b23460d51a3.

Lenovo 82TQ is unhappy if we do the display on sequence this late. The display output shows severe corruption.

It's unclear if this is a failure on our part (perhaps something to do with sending commands in LP mode after HS /video mode transmission has been started? Though the backlight on command at least seems to work) or simply that there are some commands in the sequence that are needed to be done earlier (eg. could be some DSC init stuff?). If the latter then I don't think the current Windows code would work either, but maybe this was originally tested with an older driver, who knows.

Root causing this fully would likely require a lot of experimentation which isn't really feasible without direct access to the machine, so let's just accept failure and go back to the original sequence.

Cc: stable@vger.kernel.org Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/10071 Signed-off-by: Ville Syrjälä ville.syrjala@linux.intel.com

Acked-by: Jani Nikula jani.nikula@intel.com

---

drivers/gpu/drm/i915/display/icl_dsi.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/icl_dsi.c b/drivers/gpu/drm/i915/display/icl_dsi.c index ac456a2275db..eda4a8b88590 100644 --- a/drivers/gpu/drm/i915/display/icl_dsi.c +++ b/drivers/gpu/drm/i915/display/icl_dsi.c @@ -1155,6 +1155,7 @@ static void gen11_dsi_powerup_panel(struct intel_encoder *encoder) } intel_dsi_vbt_exec_sequence(intel_dsi, MIPI_SEQ_INIT_OTP);

• intel_dsi_vbt_exec_sequence(intel_dsi, MIPI_SEQ_DISPLAY_ON);

/* ensure all panel commands dispatched before enabling transcoder */ wait_for_cmds_dispatched_to_panel(encoder); @@ -1255,8 +1256,6 @@ static void gen11_dsi_enable(struct intel_atomic_state *state, /* step6d: enable dsi transcoder */ gen11_dsi_enable_transcoder(encoder);

• intel_dsi_vbt_exec_sequence(intel_dsi, MIPI_SEQ_DISPLAY_ON);
• /* step7: enable backlight */ intel_backlight_enable(crtc_state, conn_state); intel_dsi_vbt_exec_sequence(intel_dsi, MIPI_SEQ_BACKLIGHT_ON);