drm/amd/display: Fix 128b132b link loss handling

[Why]
We don't check 128b132b-specific bits in LANE_ALIGN_STATUS_UPDATED DPCD
registers when parsing link loss status, which can cause us to miss a
link loss notification from some sinks.

[How]
Add a 128b132b-specific status bit check.

Cc: stable@vger.kernel.org # 6.3+
Reviewed-by: Wenjing Liu <wenjing.liu@amd.com>
Acked-by: Hamza Mahfooz <hamza.mahfooz@amd.com>
Signed-off-by: Ilya Bakoulin <ilya.bakoulin@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_irq_handler.c b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_irq_handler.c
index ba95fac..b1b11eb 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_irq_handler.c
+++ b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_irq_handler.c
@@ -82,8 +82,15 @@ bool dp_parse_link_loss_status(
        }
 
        /* Check interlane align.*/
-       if (sink_status_changed ||
-               !hpd_irq_dpcd_data->bytes.lane_status_updated.bits.INTERLANE_ALIGN_DONE) {
+       if (link_dp_get_encoding_format(&link->cur_link_settings) == DP_128b_132b_ENCODING &&
+                       (!hpd_irq_dpcd_data->bytes.lane_status_updated.bits.EQ_INTERLANE_ALIGN_DONE_128b_132b ||
+                        !hpd_irq_dpcd_data->bytes.lane_status_updated.bits.CDS_INTERLANE_ALIGN_DONE_128b_132b)) {
+               sink_status_changed = true;
+       } else if (!hpd_irq_dpcd_data->bytes.lane_status_updated.bits.INTERLANE_ALIGN_DONE) {
+               sink_status_changed = true;
+       }
+
+       if (sink_status_changed) {
 
                DC_LOG_HW_HPD_IRQ("%s: Link Status changed.\n", __func__);