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authorJose Fernandez <josef@netflix.com>2024-04-22 17:35:44 +0300
committerAlex Deucher <alexander.deucher@amd.com>2024-04-27 00:22:40 +0300
commit130afc8a886183a94cf6eab7d24f300014ff87ba (patch)
treed5599eeadffe06a3d537ca927130ea911b3b0d12 /drivers/gpu/drm/amd/display/dc
parent71dfa617ea9f18e4585fe78364217cd32b1fc382 (diff)
downloadlinux-130afc8a886183a94cf6eab7d24f300014ff87ba.tar.xz
drm/amd/display: Fix division by zero in setup_dsc_config
When slice_height is 0, the division by slice_height in the calculation of the number of slices will cause a division by zero driver crash. This leaves the kernel in a state that requires a reboot. This patch adds a check to avoid the division by zero. The stack trace below is for the 6.8.4 Kernel. I reproduced the issue on a Z16 Gen 2 Lenovo Thinkpad with a Apple Studio Display monitor connected via Thunderbolt. The amdgpu driver crashed with this exception when I rebooted the system with the monitor connected. kernel: ? die (arch/x86/kernel/dumpstack.c:421 arch/x86/kernel/dumpstack.c:434 arch/x86/kernel/dumpstack.c:447) kernel: ? do_trap (arch/x86/kernel/traps.c:113 arch/x86/kernel/traps.c:154) kernel: ? setup_dsc_config (drivers/gpu/drm/amd/amdgpu/../display/dc/dsc/dc_dsc.c:1053) amdgpu kernel: ? do_error_trap (./arch/x86/include/asm/traps.h:58 arch/x86/kernel/traps.c:175) kernel: ? setup_dsc_config (drivers/gpu/drm/amd/amdgpu/../display/dc/dsc/dc_dsc.c:1053) amdgpu kernel: ? exc_divide_error (arch/x86/kernel/traps.c:194 (discriminator 2)) kernel: ? setup_dsc_config (drivers/gpu/drm/amd/amdgpu/../display/dc/dsc/dc_dsc.c:1053) amdgpu kernel: ? asm_exc_divide_error (./arch/x86/include/asm/idtentry.h:548) kernel: ? setup_dsc_config (drivers/gpu/drm/amd/amdgpu/../display/dc/dsc/dc_dsc.c:1053) amdgpu kernel: dc_dsc_compute_config (drivers/gpu/drm/amd/amdgpu/../display/dc/dsc/dc_dsc.c:1109) amdgpu After applying this patch, the driver no longer crashes when the monitor is connected and the system is rebooted. I believe this is the same issue reported for 3113. Reviewed-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com> Signed-off-by: Jose Fernandez <josef@netflix.com> Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/3113 Signed-off-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Diffstat (limited to 'drivers/gpu/drm/amd/display/dc')
-rw-r--r--drivers/gpu/drm/amd/display/dc/dsc/dc_dsc.c7
1 files changed, 6 insertions, 1 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 a15b21edb0cc..150ef23440a2 100644
--- a/drivers/gpu/drm/amd/display/dc/dsc/dc_dsc.c
+++ b/drivers/gpu/drm/amd/display/dc/dsc/dc_dsc.c
@@ -1055,7 +1055,12 @@ static bool setup_dsc_config(
if (!is_dsc_possible)
goto done;
- dsc_cfg->num_slices_v = pic_height/slice_height;
+ if (slice_height > 0) {
+ dsc_cfg->num_slices_v = pic_height / slice_height;
+ } else {
+ is_dsc_possible = false;
+ goto done;
+ }
if (target_bandwidth_kbps > 0) {
is_dsc_possible = decide_dsc_target_bpp_x16(