This is a note to let you know that I've just added the patch titled
drm/amd/display: Fallback to clocks which meet requested voltage on DCN31
to the 5.14-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-fallback-to-clocks-which-meet-requested-voltage-on-dcn31.patch
and it can be found in the queue-5.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 54149d13f369e1ab02f36b91feee02069184c1d8 Mon Sep 17 00:00:00 2001
From: Michael Strauss <michael.strauss@xxxxxxx>
Date: Thu, 21 Oct 2021 13:27:16 -0400
Subject: drm/amd/display: Fallback to clocks which meet requested voltage on DCN31
From: Michael Strauss <michael.strauss@xxxxxxx>
commit 54149d13f369e1ab02f36b91feee02069184c1d8 upstream.
[WHY]
On certain configs, SMU clock table voltages don't match which cause parser
to behave incorrectly by leaving dcfclk and socclk table entries unpopulated.
[HOW]
Currently the function that finds the corresponding clock for a given voltage
only checks for exact voltage level matches. In the case that no match gets
found, parser now falls back to searching for the max clock which meets the
requested voltage (i.e. its corresponding voltage is below requested).
Signed-off-by: Michael Strauss <michael.strauss@xxxxxxx>
Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas@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/clk_mgr/dcn31/dcn31_clk_mgr.c | 13 ++++++++---
1 file changed, 10 insertions(+), 3 deletions(-)
--- a/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn31/dcn31_clk_mgr.c
+++ b/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn31/dcn31_clk_mgr.c
@@ -518,14 +518,21 @@ static unsigned int find_clk_for_voltage
unsigned int voltage)
{
int i;
+ int max_voltage = 0;
+ int clock = 0;
for (i = 0; i < NUM_SOC_VOLTAGE_LEVELS; i++) {
- if (clock_table->SocVoltage[i] == voltage)
+ if (clock_table->SocVoltage[i] == voltage) {
return clocks[i];
+ } else if (clock_table->SocVoltage[i] >= max_voltage &&
+ clock_table->SocVoltage[i] < voltage) {
+ max_voltage = clock_table->SocVoltage[i];
+ clock = clocks[i];
+ }
}
- ASSERT(0);
- return 0;
+ ASSERT(clock);
+ return clock;
}
void dcn31_clk_mgr_helper_populate_bw_params(
Patches currently in stable-queue which might be from michael.strauss@xxxxxxx are
queue-5.14/drm-amd-display-fallback-to-clocks-which-meet-requested-voltage-on-dcn31.patch
