drm/i915/dsi: Execute MIPI_SEQ_DEASSERT_RESET before calling device_ready()

Execute MIPI_SEQ_DEASSERT_RESET before putting the device in ready
state (LP-11), this is the sequence in which things should be done
according to the spec.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Bob Paauwe <bob.j.paauwe@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1488374106-4949-6-git-send-email-jani.nikula@intel.com

drivers/gpu/drm/i915/intel_dsi.c

@@ -808,10 +808,13 @@ static void intel_dsi_pre_enable(struct intel_encoder *encoder,
 	intel_dsi_exec_vbt_sequence(intel_dsi, MIPI_SEQ_POWER_ON);
 	msleep(intel_dsi->panel_on_delay);
 
-	/* put device in ready state */
+	/* Deassert reset */
+	intel_dsi_exec_vbt_sequence(intel_dsi, MIPI_SEQ_DEASSERT_RESET);
+
+	/* Put device in ready state (LP-11) */
 	intel_dsi_device_ready(encoder);
 
-	intel_dsi_exec_vbt_sequence(intel_dsi, MIPI_SEQ_DEASSERT_RESET);
+	/* Send initialization commands in LP mode */
 	intel_dsi_exec_vbt_sequence(intel_dsi, MIPI_SEQ_INIT_OTP);
 
 	/* Enable port in pre-enable phase itself because as per hw team
@@ -915,6 +918,7 @@ static void intel_dsi_post_disable(struct intel_encoder *encoder,
 	intel_dsi_exec_vbt_sequence(intel_dsi, MIPI_SEQ_BACKLIGHT_OFF);
 	intel_dsi_exec_vbt_sequence(intel_dsi, MIPI_SEQ_DISPLAY_OFF);
 
+	/* Transition to LP-00 */
 	intel_dsi_clear_device_ready(encoder);
 
 	if (IS_BROXTON(dev_priv)) {
@@ -938,6 +942,7 @@ static void intel_dsi_post_disable(struct intel_encoder *encoder,
 		I915_WRITE(DSPCLK_GATE_D, val);
 	}
 
+	/* Assert reset */
 	intel_dsi_exec_vbt_sequence(intel_dsi, MIPI_SEQ_ASSERT_RESET);
 
 	/* Power off, try both CRC pmic gpio and VBT */