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From: Ville Syrjala <ville.syrjala@linux.intel.com>
To: intel-gfx@lists.freedesktop.org
Cc: stable@vger.kernel.org
Subject: [PATCH] drm/i915/dp: Limit SST link rate to <=8.1Gbps
Date: Thu,  8 Feb 2024 17:45:52 +0200	[thread overview]
Message-ID: <20240208154552.14545-1-ville.syrjala@linux.intel.com> (raw)

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

Limit the link rate to HBR3 or below (<=8.1Gbps) in SST mode.
UHBR (10Gbps+) link rates require 128b/132b channel encoding
which we have not yet hooked up into the SST/no-sideband codepaths.

Cc: stable@vger.kernel.org
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
---
 drivers/gpu/drm/i915/display/intel_dp.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index ab415f41924d..5045c34a16be 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -2356,6 +2356,9 @@ intel_dp_compute_config_limits(struct intel_dp *intel_dp,
 	limits->min_rate = intel_dp_common_rate(intel_dp, 0);
 	limits->max_rate = intel_dp_max_link_rate(intel_dp);
 
+	/* FIXME 128b/132b SST support missing */
+	limits->max_rate = min(limits->max_rate, 810000);
+
 	limits->min_lane_count = 1;
 	limits->max_lane_count = intel_dp_max_lane_count(intel_dp);
 
-- 
2.43.0


             reply	other threads:[~2024-02-08 15:45 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-02-08 15:45 Ville Syrjala [this message]
2024-02-08 15:55 ` [PATCH] drm/i915/dp: Limit SST link rate to <=8.1Gbps Jani Nikula
2024-02-08 23:05 ` ✓ Fi.CI.BAT: success for " Patchwork
2024-02-09  5:25 ` ✗ Fi.CI.IGT: failure " Patchwork

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