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[5/5] drm/i915/dp: Disable Port sync mode correctly on teardown

Message ID 20191210223238.12022-6-manasi.d.navare@intel.com (mailing list archive)
State New, archived
Headers show
Series DRM and i915 fixes to handle hotplug/unplug for 8K tiled displays | expand

Commit Message

Navare, Manasi Dec. 10, 2019, 10:32 p.m. UTC
While clearing the Ports ync mode enable and master select bits
we need to make sure that we perform a RMW for disable else
it sets the other bits casuing unwanted sideeffects.

Bugzilla: https://gitlab.freedesktop.org/drm/intel/issues/5
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Fixes: 51528afe7c5e ("drm/i915/display/icl: Disable transcoder port sync as part of crtc_disable() sequence")
Signed-off-by: Manasi Navare <manasi.d.navare@intel.com>
---
 drivers/gpu/drm/i915/display/intel_display.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
index c0a2dab3fe67..3fccda0f1f36 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -4599,7 +4599,8 @@  static void icl_disable_transcoder_port_sync(const struct intel_crtc_state *old_
 		      transcoder_name(old_crtc_state->cpu_transcoder));
 
 	reg = TRANS_DDI_FUNC_CTL2(old_crtc_state->cpu_transcoder);
-	trans_ddi_func_ctl2_val = ~(PORT_SYNC_MODE_ENABLE |
+	trans_ddi_func_ctl2_val = I915_READ(reg);
+	trans_ddi_func_ctl2_val &= ~(PORT_SYNC_MODE_ENABLE |
 				    PORT_SYNC_MODE_MASTER_SELECT_MASK);
 	I915_WRITE(reg, trans_ddi_func_ctl2_val);
 }