[PATCH] drm/amd/dc: Read from DP_SINK_COUNT_ESI for DPDC r1.2 or higher

Wayne Lin Wayne.Lin at amd.com
Tue Aug 4 03:42:18 UTC 2020


[Why]
According to DP spec, DPRX with DPCD r1.2 or higher shall have the
same Link/Sink Device Status field registers at DPCD Addresses 00200h
through 00205h to the corresponding DPRX Event Status Indicator
registers at DPCD Addresses 02002h through 0200Fh. We now only read from
02002h when DPCD revision number is r1.4 or higher while handling short
HPD. Need to correct that.

[How]
Set to read from 02002h when DPCD is r1.2 or higher

Signed-off-by: Wayne Lin <Wayne.Lin at amd.com>
---
 drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
index 2bfa4e35c2cf..9fb1543b4c73 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
@@ -1834,9 +1834,9 @@ static enum dc_status read_hpd_rx_irq_data(
 	 * fail, so we now explicitly read 6 bytes which is
 	 * the req from the above mentioned test cases.
 	 *
-	 * For DP 1.4 we need to read those from 2002h range.
+	 * For DPCD r1.2 or higher, we need to read those from 2002h range.
 	 */
-	if (link->dpcd_caps.dpcd_rev.raw < DPCD_REV_14)
+	if (link->dpcd_caps.dpcd_rev.raw < DPCD_REV_12)
 		retval = core_link_read_dpcd(
 			link,
 			DP_SINK_COUNT,
-- 
2.17.1



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