This is a note to let you know that I've just added the patch titled
drm/amd/display: Fix reg timeout in enc314_enable_fifo
to the 6.0-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-fix-reg-timeout-in-enc314_enable_fifo.patch
and it can be found in the queue-6.0 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From ce62198d8b62734a985d22652e75a649be052390 Mon Sep 17 00:00:00 2001
From: Nicholas Kazlauskas <nicholas.kazlauskas@xxxxxxx>
Date: Thu, 27 Oct 2022 15:34:33 -0400
Subject: drm/amd/display: Fix reg timeout in enc314_enable_fifo
From: Nicholas Kazlauskas <nicholas.kazlauskas@xxxxxxx>
commit ce62198d8b62734a985d22652e75a649be052390 upstream.
[Why]
The link enablement sequence can end up resetting the encoder while
the PHY symclk isn't yet on.
This means that waiting for symclk on will timeout, along with the reset
bit never asserting high.
This causes unnecessary delay when enabling the link and produces a
warning affecting multiple IGT tests.
[How]
Don't wait for the symclk to be on here because firmware already does.
Don't wait for reset if we know the symclk isn't on.
Split the reset into a helper function that checks the bit and decides
whether or not a delay is sufficient.
Reviewed-by: Roman Li <Roman.Li@xxxxxxx>
Acked-by: Alan Liu <HaoPing.Liu@xxxxxxx>
Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@xxxxxxx>
Tested-by: Daniel Wheeler <daniel.wheeler@xxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx # 6.0.x
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
.../dc/dcn314/dcn314_dio_stream_encoder.c | 24 ++++++++++++++-----
1 file changed, 18 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/amd/display/dc/dcn314/dcn314_dio_stream_encoder.c b/drivers/gpu/drm/amd/display/dc/dcn314/dcn314_dio_stream_encoder.c
index 7e773bf7b895..38842f938bed 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn314/dcn314_dio_stream_encoder.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn314/dcn314_dio_stream_encoder.c
@@ -49,18 +49,30 @@
#define CTX \
enc1->base.ctx
+static void enc314_reset_fifo(struct stream_encoder *enc, bool reset)
+{
+ struct dcn10_stream_encoder *enc1 = DCN10STRENC_FROM_STRENC(enc);
+ uint32_t reset_val = reset ? 1 : 0;
+ uint32_t is_symclk_on;
+
+ REG_UPDATE(DIG_FIFO_CTRL0, DIG_FIFO_RESET, reset_val);
+ REG_GET(DIG_FE_CNTL, DIG_SYMCLK_FE_ON, &is_symclk_on);
+
+ if (is_symclk_on)
+ REG_WAIT(DIG_FIFO_CTRL0, DIG_FIFO_RESET_DONE, reset_val, 10, 5000);
+ else
+ udelay(10);
+}
static void enc314_enable_fifo(struct stream_encoder *enc)
{
struct dcn10_stream_encoder *enc1 = DCN10STRENC_FROM_STRENC(enc);
- /* TODO: Confirm if we need to wait for DIG_SYMCLK_FE_ON */
- REG_WAIT(DIG_FE_CNTL, DIG_SYMCLK_FE_ON, 1, 10, 5000);
REG_UPDATE(DIG_FIFO_CTRL0, DIG_FIFO_READ_START_LEVEL, 0x7);
- REG_UPDATE(DIG_FIFO_CTRL0, DIG_FIFO_RESET, 1);
- REG_WAIT(DIG_FIFO_CTRL0, DIG_FIFO_RESET_DONE, 1, 10, 5000);
- REG_UPDATE(DIG_FIFO_CTRL0, DIG_FIFO_RESET, 0);
- REG_WAIT(DIG_FIFO_CTRL0, DIG_FIFO_RESET_DONE, 0, 10, 5000);
+
+ enc314_reset_fifo(enc, true);
+ enc314_reset_fifo(enc, false);
+
REG_UPDATE(DIG_FIFO_CTRL0, DIG_FIFO_ENABLE, 1);
}
--
2.38.1
Patches currently in stable-queue which might be from nicholas.kazlauskas@xxxxxxx are
queue-6.0/drm-amd-display-update-sr-watermarks-for-dcn314.patch
queue-6.0/drm-amd-display-fix-reg-timeout-in-enc314_enable_fifo.patch
