This is a note to let you know that I've just added the patch titled
drm/amd/display: Implement workaround for writing to OTG_PIXEL_RATE_DIV register
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drm-amd-display-implement-workaround-for-writing-to-otg_pixel_rate_div-register.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 74fa4c81aadf418341f0d073c864ea7dca730a2e Mon Sep 17 00:00:00 2001
From: Saaem Rizvi <SyedSaaem.Rizvi@xxxxxxx>
Date: Mon, 6 Mar 2023 15:10:13 -0500
Subject: drm/amd/display: Implement workaround for writing to OTG_PIXEL_RATE_DIV register
From: Saaem Rizvi <SyedSaaem.Rizvi@xxxxxxx>
commit 74fa4c81aadf418341f0d073c864ea7dca730a2e upstream.
[Why and How]
Current implementation requires FPGA builds to take a different
code path from DCN32 to write to OTG_PIXEL_RATE_DIV. Now that
we have a workaround to write to OTG_PIXEL_RATE_DIV register without
blanking display on hotplug on DCN32, we can allow the code paths for
FPGA to be exactly the same allowing for more consistent
testing.
Reviewed-by: Alvin Lee <Alvin.Lee2@xxxxxxx>
Acked-by: Qingqing Zhuo <qingqing.zhuo@xxxxxxx>
Signed-off-by: Saaem Rizvi <SyedSaaem.Rizvi@xxxxxxx>
Tested-by: Daniel Wheeler <daniel.wheeler@xxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Cc: "Limonciello, Mario" <mario.limonciello@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/amd/display/dc/dcn20/dcn20_dccg.h | 3 +-
drivers/gpu/drm/amd/display/dc/dcn32/dcn32_dccg.c | 22 ++++++++++++++++++
drivers/gpu/drm/amd/display/dc/dcn32/dcn32_dccg.h | 3 +-
drivers/gpu/drm/amd/display/dc/dcn32/dcn32_hwseq.c | 2 -
drivers/gpu/drm/amd/display/dc/dcn32/dcn32_resource.h | 3 +-
5 files changed, 29 insertions(+), 4 deletions(-)
--- a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_dccg.h
+++ b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_dccg.h
@@ -230,7 +230,8 @@
type DTBCLK_P2_SRC_SEL;\
type DTBCLK_P2_EN;\
type DTBCLK_P3_SRC_SEL;\
- type DTBCLK_P3_EN;
+ type DTBCLK_P3_EN;\
+ type DENTIST_DISPCLK_CHG_DONE;
struct dccg_shift {
DCCG_REG_FIELD_LIST(uint8_t)
--- a/drivers/gpu/drm/amd/display/dc/dcn32/dcn32_dccg.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn32/dcn32_dccg.c
@@ -42,6 +42,20 @@
#define DC_LOGGER \
dccg->ctx->logger
+/* This function is a workaround for writing to OTG_PIXEL_RATE_DIV
+ * without the probability of causing a DIG FIFO error.
+ */
+static void dccg32_wait_for_dentist_change_done(
+ struct dccg *dccg)
+{
+ struct dcn_dccg *dccg_dcn = TO_DCN_DCCG(dccg);
+
+ uint32_t dentist_dispclk_value = REG_READ(DENTIST_DISPCLK_CNTL);
+
+ REG_WRITE(DENTIST_DISPCLK_CNTL, dentist_dispclk_value);
+ REG_WAIT(DENTIST_DISPCLK_CNTL, DENTIST_DISPCLK_CHG_DONE, 1, 50, 2000);
+}
+
static void dccg32_get_pixel_rate_div(
struct dccg *dccg,
uint32_t otg_inst,
@@ -110,21 +124,29 @@ static void dccg32_set_pixel_rate_div(
REG_UPDATE_2(OTG_PIXEL_RATE_DIV,
OTG0_PIXEL_RATE_DIVK1, k1,
OTG0_PIXEL_RATE_DIVK2, k2);
+
+ dccg32_wait_for_dentist_change_done(dccg);
break;
case 1:
REG_UPDATE_2(OTG_PIXEL_RATE_DIV,
OTG1_PIXEL_RATE_DIVK1, k1,
OTG1_PIXEL_RATE_DIVK2, k2);
+
+ dccg32_wait_for_dentist_change_done(dccg);
break;
case 2:
REG_UPDATE_2(OTG_PIXEL_RATE_DIV,
OTG2_PIXEL_RATE_DIVK1, k1,
OTG2_PIXEL_RATE_DIVK2, k2);
+
+ dccg32_wait_for_dentist_change_done(dccg);
break;
case 3:
REG_UPDATE_2(OTG_PIXEL_RATE_DIV,
OTG3_PIXEL_RATE_DIVK1, k1,
OTG3_PIXEL_RATE_DIVK2, k2);
+
+ dccg32_wait_for_dentist_change_done(dccg);
break;
default:
BREAK_TO_DEBUGGER();
--- a/drivers/gpu/drm/amd/display/dc/dcn32/dcn32_dccg.h
+++ b/drivers/gpu/drm/amd/display/dc/dcn32/dcn32_dccg.h
@@ -147,7 +147,8 @@
DCCG_SF(DTBCLK_P_CNTL, DTBCLK_P3_SRC_SEL, mask_sh),\
DCCG_SF(DTBCLK_P_CNTL, DTBCLK_P3_EN, mask_sh),\
DCCG_SF(DCCG_AUDIO_DTO_SOURCE, DCCG_AUDIO_DTO_SEL, mask_sh),\
- DCCG_SF(DCCG_AUDIO_DTO_SOURCE, DCCG_AUDIO_DTO0_SOURCE_SEL, mask_sh)
+ DCCG_SF(DCCG_AUDIO_DTO_SOURCE, DCCG_AUDIO_DTO0_SOURCE_SEL, mask_sh),\
+ DCCG_SF(DENTIST_DISPCLK_CNTL, DENTIST_DISPCLK_CHG_DONE, mask_sh)
struct dccg *dccg32_create(
--- a/drivers/gpu/drm/amd/display/dc/dcn32/dcn32_hwseq.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn32/dcn32_hwseq.c
@@ -1177,7 +1177,7 @@ unsigned int dcn32_calculate_dccg_k1_k2_
*k2_div = PIXEL_RATE_DIV_BY_2;
else
*k2_div = PIXEL_RATE_DIV_BY_4;
- } else if (dc_is_dp_signal(stream->signal)) {
+ } else if (dc_is_dp_signal(stream->signal) || dc_is_virtual_signal(stream->signal)) {
if (two_pix_per_container) {
*k1_div = PIXEL_RATE_DIV_BY_1;
*k2_div = PIXEL_RATE_DIV_BY_2;
--- a/drivers/gpu/drm/amd/display/dc/dcn32/dcn32_resource.h
+++ b/drivers/gpu/drm/amd/display/dc/dcn32/dcn32_resource.h
@@ -1272,7 +1272,8 @@ unsigned int dcn32_calc_num_avail_chans_
DCCG_SRII(PHASE, DTBCLK_DTO, 0), DCCG_SRII(PHASE, DTBCLK_DTO, 1), \
DCCG_SRII(PHASE, DTBCLK_DTO, 2), DCCG_SRII(PHASE, DTBCLK_DTO, 3), \
SR(DCCG_AUDIO_DTBCLK_DTO_MODULO), SR(DCCG_AUDIO_DTBCLK_DTO_PHASE), \
- SR(OTG_PIXEL_RATE_DIV), SR(DTBCLK_P_CNTL), SR(DCCG_AUDIO_DTO_SOURCE) \
+ SR(OTG_PIXEL_RATE_DIV), SR(DTBCLK_P_CNTL), \
+ SR(DCCG_AUDIO_DTO_SOURCE), SR(DENTIST_DISPCLK_CNTL) \
)
/* VMID */
Patches currently in stable-queue which might be from SyedSaaem.Rizvi@xxxxxxx are
queue-6.1/drm-amd-display-implement-workaround-for-writing-to-otg_pixel_rate_div-register.patch
