When disabling pattern training after successful link training the
CH7511 bridge incorrectly clears the INTERLANE_ALIGN_DONE bit. This is
interpreted as link failure when rechecking the link status and triggers
an endless loop of retraining sequences.
This patch adds a quirk to pretend the bit is still set and no
retraining is needed.
Fixes: 3b3be899fc81 ("drm/i915/dp: Recheck link state after modeset")
Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/work_items/15744
Signed-off-by: Patrik Jakobsson <[email protected]>
---
v2 changes:
- Added "Closes" tag
drivers/gpu/drm/i915/display/intel_dp.c | 9 +++++++++
drivers/gpu/drm/i915/display/intel_quirks.c | 17 +++++++++++++++++
drivers/gpu/drm/i915/display/intel_quirks.h | 1 +
3 files changed, 27 insertions(+)
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c
b/drivers/gpu/drm/i915/display/intel_dp.c
index 85d3aa3b9894..5b269b1f18d7 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -5875,6 +5875,15 @@ intel_dp_needs_link_retrain(struct intel_dp *intel_dp)
if (intel_dp->link.seq_train_failures)
return true;
+ /*
+ * The CH7511 bridge incorrectly clears the INTERLANE_ALIGN_DONE bit
+ * when disabling training pattern.
+ */
+ if (intel_has_dpcd_quirk(intel_dp, QUIRK_IGNORE_INTERLANE_ALIGN_BIT)) {
+ link_status[DP_LANE_ALIGN_STATUS_UPDATED - DP_LANE0_1_STATUS] |=
+ DP_INTERLANE_ALIGN_DONE;
+ }
+
/* Retrain if link not ok */
return !intel_dp_link_ok(intel_dp, link_status) &&
!intel_psr_link_ok(intel_dp);
diff --git a/drivers/gpu/drm/i915/display/intel_quirks.c
b/drivers/gpu/drm/i915/display/intel_quirks.c
index 33245f44c0d5..2cec0a945528 100644
--- a/drivers/gpu/drm/i915/display/intel_quirks.c
+++ b/drivers/gpu/drm/i915/display/intel_quirks.c
@@ -100,6 +100,14 @@ static void quirk_disable_psr2(struct intel_display
*display)
drm_info(display->drm, "PSR2 support not currently available for this
setup, applying disable PSR2 quirk\n");
}
+static void quirk_ignore_interlane_align_bit(struct intel_dp *intel_dp)
+{
+ struct intel_display *display = to_intel_display(intel_dp);
+
+ intel_set_dpcd_quirk(intel_dp, QUIRK_IGNORE_INTERLANE_ALIGN_BIT);
+ drm_info(display->drm, "Applying ignore interlane align bit quirk\n");
+}
+
struct intel_quirk {
int device;
int subsystem_vendor;
@@ -286,6 +294,15 @@ static const struct intel_dpcd_quirk intel_dpcd_quirks[] =
{
.sink_oui = SINK_OUI(0x00, 0x22, 0xb9),
.hook = quirk_disable_edp_panel_replay,
},
+ /* Nodka TPC6000-C152 */
+ {
+ .device = 0x0f31,
+ .subsystem_vendor = 0x8086,
+ .subsystem_device = 0x0f31,
+ .sink_oui = SINK_OUI(0x2b, 0x02, 0xf0),
+ .sink_device_id = SINK_DEVICE_ID('C', 'H', '7', '5', '1', '1'),
+ .hook = quirk_ignore_interlane_align_bit,
+ },
};
void intel_init_quirks(struct intel_display *display)
diff --git a/drivers/gpu/drm/i915/display/intel_quirks.h
b/drivers/gpu/drm/i915/display/intel_quirks.h
index 970a4fe52faf..7fcc3967f84f 100644
--- a/drivers/gpu/drm/i915/display/intel_quirks.h
+++ b/drivers/gpu/drm/i915/display/intel_quirks.h
@@ -23,6 +23,7 @@ enum intel_quirk_id {
QUIRK_EDP_LIMIT_RATE_HBR2,
QUIRK_DISABLE_EDP_PANEL_REPLAY,
QUIRK_DISABLE_PSR2,
+ QUIRK_IGNORE_INTERLANE_ALIGN_BIT,
};
void intel_init_quirks(struct intel_display *display);
--
2.54.0
