summaryrefslogtreecommitdiff
path: root/drivers/gpu
diff options
context:
space:
mode:
authorTaimur Hassan <Syed.Hassan@amd.com>2022-09-13 18:35:20 -0400
committerAlex Deucher <alexander.deucher@amd.com>2022-09-27 17:59:07 -0400
commita28acf7091babf4248b042326946cee7736f796a (patch)
treec00e02c8a6d6b373432a8aa84c6edf9145afb5b3 /drivers/gpu
parent8dd2e87dbd49ba0b6afc1dd22a5930d797cf423f (diff)
drm/amd/display: Avoid unnecessary pixel rate divider programming
[Why] Programming pixel rate divider when FIFO is enabled can cause FIFO error. [How] Skip divider programming when divider values are the same to prevent FIFO error. Reviewed-by: Alvin Lee <alvin.lee2@amd.com> Acked-by: Jasdeep Dhillon <jdhillon@amd.com> Signed-off-by: Taimur Hassan <Syed.Hassan@amd.com> Tested-by: Daniel Wheeler <daniel.wheeler@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Diffstat (limited to 'drivers/gpu')
-rw-r--r--drivers/gpu/drm/amd/display/dc/dcn32/dcn32_dccg.c53
1 files changed, 53 insertions, 0 deletions
diff --git a/drivers/gpu/drm/amd/display/dc/dcn32/dcn32_dccg.c b/drivers/gpu/drm/amd/display/dc/dcn32/dcn32_dccg.c
index 0d5e8a441512..6640d0ac4304 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn32/dcn32_dccg.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn32/dcn32_dccg.c
@@ -42,6 +42,48 @@
#define DC_LOGGER \
dccg->ctx->logger
+static void dccg32_get_pixel_rate_div(
+ struct dccg *dccg,
+ uint32_t otg_inst,
+ enum pixel_rate_div *k1,
+ enum pixel_rate_div *k2)
+{
+ struct dcn_dccg *dccg_dcn = TO_DCN_DCCG(dccg);
+ uint32_t val_k1 = PIXEL_RATE_DIV_NA, val_k2 = PIXEL_RATE_DIV_NA;
+
+ *k1 = PIXEL_RATE_DIV_NA;
+ *k2 = PIXEL_RATE_DIV_NA;
+
+ switch (otg_inst) {
+ case 0:
+ REG_GET_2(OTG_PIXEL_RATE_DIV,
+ OTG0_PIXEL_RATE_DIVK1, &val_k1,
+ OTG0_PIXEL_RATE_DIVK2, &val_k2);
+ break;
+ case 1:
+ REG_GET_2(OTG_PIXEL_RATE_DIV,
+ OTG1_PIXEL_RATE_DIVK1, &val_k1,
+ OTG1_PIXEL_RATE_DIVK2, &val_k2);
+ break;
+ case 2:
+ REG_GET_2(OTG_PIXEL_RATE_DIV,
+ OTG2_PIXEL_RATE_DIVK1, &val_k1,
+ OTG2_PIXEL_RATE_DIVK2, &val_k2);
+ break;
+ case 3:
+ REG_GET_2(OTG_PIXEL_RATE_DIV,
+ OTG3_PIXEL_RATE_DIVK1, &val_k1,
+ OTG3_PIXEL_RATE_DIVK2, &val_k2);
+ break;
+ default:
+ BREAK_TO_DEBUGGER();
+ return;
+ }
+
+ *k1 = (enum pixel_rate_div)val_k1;
+ *k2 = (enum pixel_rate_div)val_k2;
+}
+
static void dccg32_set_pixel_rate_div(
struct dccg *dccg,
uint32_t otg_inst,
@@ -50,6 +92,17 @@ static void dccg32_set_pixel_rate_div(
{
struct dcn_dccg *dccg_dcn = TO_DCN_DCCG(dccg);
+ enum pixel_rate_div cur_k1 = PIXEL_RATE_DIV_NA, cur_k2 = PIXEL_RATE_DIV_NA;
+
+ // Don't program 0xF into the register field. Not valid since
+ // K1 / K2 field is only 1 / 2 bits wide
+ if (k1 == PIXEL_RATE_DIV_NA || k2 == PIXEL_RATE_DIV_NA)
+ return;
+
+ dccg32_get_pixel_rate_div(dccg, otg_inst, &cur_k1, &cur_k2);
+ if (k1 == cur_k1 && k2 == cur_k2)
+ return;
+
switch (otg_inst) {
case 0:
REG_UPDATE_2(OTG_PIXEL_RATE_DIV,