This patch may be related and conflict to
https://www.mail-archive.com/[email protected]/msg125873.html
amd-staging-drm-next should include the above patch but it is not
updated for 2 weeks, so let's wait for ASDN to be updated.
On 7/24/25 16:32, Rodrigo Siqueira wrote:
On 010/22, Timur Kristóf wrote:
After refactoring the DSC capability calculation, the
get_min_slice_count_for_odm could crash on some GPUs due to a
division by zero when max_total_throughput_mps was zero.
As a result, DC was broken when connecting a GPU that doesn't
support DSC to a monitor that supports DSC.
Tested on Oland (DCE 6) and Fiji (DCE 10).
This commit fixes it by returning zero instead.
Fixes: 4909b8b3846c ("drm/amd/display: Refactor DSC cap calculations")
Signed-off-by: Timur Kristóf <[email protected]>
---
drivers/gpu/drm/amd/display/dc/dsc/dc_dsc.c | 17 +++++++++--------
1 file changed, 9 insertions(+), 8 deletions(-)
diff --git a/drivers/gpu/drm/amd/display/dc/dsc/dc_dsc.c
b/drivers/gpu/drm/amd/display/dc/dsc/dc_dsc.c
index a454d16e6586..4169ece9c535 100644
--- a/drivers/gpu/drm/amd/display/dc/dsc/dc_dsc.c
+++ b/drivers/gpu/drm/amd/display/dc/dsc/dc_dsc.c
@@ -642,14 +642,15 @@ static unsigned int get_min_slice_count_for_odm(
unsigned int max_dispclk_khz;
/* get max pixel rate and combine caps */
- max_dispclk_khz = dsc_enc_caps->max_total_throughput_mps * 1000;
- if (dsc && dsc->ctx->dc) {
- if (dsc->ctx->dc->clk_mgr &&
- dsc->ctx->dc->clk_mgr->funcs->get_max_clock_khz) {
- /* dispclk is available */
- max_dispclk_khz =
dsc->ctx->dc->clk_mgr->funcs->get_max_clock_khz(dsc->ctx->dc->clk_mgr,
CLK_TYPE_DISPCLK);
- }
- }
+ if (dsc && dsc->ctx->dc && dsc->ctx->dc->clk_mgr &&
+ dsc->ctx->dc->clk_mgr->funcs->get_max_clock_khz)
+ max_dispclk_khz =
+ dsc->ctx->dc->clk_mgr->funcs->get_max_clock_khz(
+ dsc->ctx->dc->clk_mgr, CLK_TYPE_DISPCLK);
+ else if (dsc_enc_caps->max_total_throughput_mps)
+ max_dispclk_khz = dsc_enc_caps->max_total_throughput_mps * 1000;
+ else
+ return 0;
/* consider minimum odm slices required due to
* 1) display pipe throughput (dispclk)
--
2.50.1
This patch lgtm.
Reviewed-by: Rodrigo Siqueira <[email protected]>
I added other display folks to this patch.
I'm not sure if the original modification (4909b8b3846c) is already in
the stable kernel; if so, it could be a good idea to send this fix to
the stable kernel as well.
Thanks
