[Intel-gfx] [PATCH] drm/i915/dsi: Always use unconditional msleep() for the panel_on_delay

[Hans de Goede <hdegoede@redhat.com>]

The intel_dsi_msleep() helper skips sleeping if the MIPI-sequences have
a version of 3 or newer and the panel is in vid-mode.

This is based on the big comment around line 730 which starts with
"Panel enable/disable sequences from the VBT spec.", where
the "v3 video mode seq" column does not have any wait t# entries.

Commit 6fdb335f1c9c ("drm/i915/dsi: Use unconditional msleep for
the panel_on_delay when there is no reset-deassert MIPI-sequence")
switched to a direct msleep() instead of intel_dsi_msleep()
when there is no MIPI_SEQ_DEASSERT_RESET sequence, to fix
the panel on an Acer Aspire Switch 10 E SW3-016 not turning on.

This was done under the assumption that when there is a v3
MIPI_SEQ_DEASSERT_RESET sequence it will take care of any
necessary delays.

On the Nextbook Ares 8A (a Cherry Trail device like the Acer SW3-016)
there is a MIPI_SEQ_DEASSERT_RESET sequence, yet panel_on_delay
must still be honored otherwise the panel will not turn on.

Switch to always using an unconditional msleep() for
the panel_on_delay instead of making this depend on
the presence of a MIPI_SEQ_DEASSERT_RESET sequence.

Fixes: 6fdb335f1c9c ("drm/i915/dsi: Use unconditional msleep for the panel_on_delay when there is no reset-deassert MIPI-sequence")
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 drivers/gpu/drm/i915/display/vlv_dsi.c | 18 +++---------------
 1 file changed, 3 insertions(+), 15 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/vlv_dsi.c b/drivers/gpu/drm/i915/display/vlv_dsi.c
index a6d6d8b33f3f..1b87f8f5f7fd 100644
--- a/drivers/gpu/drm/i915/display/vlv_dsi.c
+++ b/drivers/gpu/drm/i915/display/vlv_dsi.c
@@ -788,7 +788,6 @@ static void intel_dsi_pre_enable(struct intel_atomic_state *state,
 {
 	struct intel_dsi *intel_dsi = enc_to_intel_dsi(encoder);
 	struct intel_crtc *crtc = to_intel_crtc(pipe_config->uapi.crtc);
-	struct intel_connector *connector = to_intel_connector(conn_state->connector);
 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
 	enum pipe pipe = crtc->pipe;
 	enum port port;
@@ -836,21 +835,10 @@ static void intel_dsi_pre_enable(struct intel_atomic_state *state,
 	if (!IS_GEMINILAKE(dev_priv))
 		intel_dsi_prepare(encoder, pipe_config);
 
+	/* Give the panel time to power-on and then deassert its reset */
 	intel_dsi_vbt_exec_sequence(intel_dsi, MIPI_SEQ_POWER_ON);
-
-	/*
-	 * Give the panel time to power-on and then deassert its reset.
-	 * Depending on the VBT MIPI sequences version the deassert-seq
-	 * may contain the necessary delay, intel_dsi_msleep() will skip
-	 * the delay in that case. If there is no deassert-seq, then an
-	 * unconditional msleep is used to give the panel time to power-on.
-	 */
-	if (connector->panel.vbt.dsi.sequence[MIPI_SEQ_DEASSERT_RESET]) {
-		intel_dsi_msleep(intel_dsi, intel_dsi->panel_on_delay);
-		intel_dsi_vbt_exec_sequence(intel_dsi, MIPI_SEQ_DEASSERT_RESET);
-	} else {
-		msleep(intel_dsi->panel_on_delay);
-	}
+	msleep(intel_dsi->panel_on_delay);
+	intel_dsi_vbt_exec_sequence(intel_dsi, MIPI_SEQ_DEASSERT_RESET);
 
 	if (IS_GEMINILAKE(dev_priv)) {
 		glk_cold_boot = glk_dsi_enable_io(encoder);
-- 
2.39.2