[PATCH 6.6 013/158] drm/i915: Disable live M/N updates when using bigjoiner

Greg Kroah-Hartman
2024-04-23T21:42:45Z

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

[ Upstream commit 4a36e46df7aa781c756f09727d37dc2783f1ee75 ]

All joined pipes share the same transcoder/timing generator.
Currently we just do the commits per-pipe, which doesn't really
work if we need to change the timings at the same time. For
now just disable live M/N updates when bigjoiner is needed.

Cc: stable@vger.kernel.org
Tested-by: Vidya Srinivas <vidya.srinivas@intel.com>
Reviewed-by: Arun R Murthy <arun.r.murthy@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240404213441.17637-5-ville.syrjala@linux.intel.com
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
(cherry picked from commit ef79820db723a2a7c229a7251c12859e7e25a247)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/gpu/drm/i915/display/intel_dp.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 7e135ed8e1d75..ccc47cf4d15d8 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -2148,7 +2148,11 @@ intel_dp_drrs_compute_config(struct intel_connector *connector,
intel_panel_downclock_mode(connector, &pipe_config->hw.adjusted_mode);
int pixel_clock;

- if (has_seamless_m_n(connector))
+ /*
+ * FIXME all joined pipes share the same transcoder.
+ * Need to account for that when updating M/N live.
+ */
+ if (has_seamless_m_n(connector) && !pipe_config->bigjoiner_pipes)
pipe_config->update_m_n = true;

if (!can_enable_drrs(connector, pipe_config, downclock_mode)) {
--
2.43.0