4.18-stable review patch. If anyone has any objections, please let me know.
------------------
From: Mikita Lipski <mikita.lipski@xxxxxxx>
commit 81aca8e75c1b046865fb2badef95a0dcff6f73de upstream.
[why]
When programming tonga's connector's backend we didn't take
in account that HDMI's colour depth might be more than 8bpc
therefore we need to add a switch statement that would adjust
the pixel clock accordingly.
[how]
Add a switch statement updating clock by its appropriate
coefficient.
Signed-off-by: Mikita Lipski <mikita.lipski@xxxxxxx>
Reviewed-by: Charlene Liu <Charlene.Liu@xxxxxxx>
Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@xxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/amd/display/dc/bios/command_table.c | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)
--- a/drivers/gpu/drm/amd/display/dc/bios/command_table.c
+++ b/drivers/gpu/drm/amd/display/dc/bios/command_table.c
@@ -808,6 +808,24 @@ static enum bp_result transmitter_contro
* (=1: 8bpp, =1.25: 10bpp, =1.5:12bpp, =2: 16bpp)
* LVDS mode: usPixelClock = pixel clock
*/
+ if (cntl->signal == SIGNAL_TYPE_HDMI_TYPE_A) {
+ switch (cntl->color_depth) {
+ case COLOR_DEPTH_101010:
+ params.usSymClock =
+ cpu_to_le16((le16_to_cpu(params.usSymClock) * 30) / 24);
+ break;
+ case COLOR_DEPTH_121212:
+ params.usSymClock =
+ cpu_to_le16((le16_to_cpu(params.usSymClock) * 36) / 24);
+ break;
+ case COLOR_DEPTH_161616:
+ params.usSymClock =
+ cpu_to_le16((le16_to_cpu(params.usSymClock) * 48) / 24);
+ break;
+ default:
+ break;
+ }
+ }
if (EXEC_BIOS_CMD_TABLE(UNIPHYTransmitterControl, params))
result = BP_RESULT_OK;
