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author | Jose Fernandez <josef@netflix.com> | 2024-04-22 17:35:44 +0300 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-05-25 17:22:52 +0300 |
commit | 7e4f50dfc98c49b3dc6875a35c3112522fb25639 (patch) | |
tree | 4d8cc64748abef3c845f4520b7cf3abede711742 /drivers/gpu/drm/amd/display/dc | |
parent | d4a079d1466d6fd9dba12a763a008b6f43890afb (diff) | |
download | linux-7e4f50dfc98c49b3dc6875a35c3112522fb25639.tar.xz |
drm/amd/display: Fix division by zero in setup_dsc_config
commit 130afc8a886183a94cf6eab7d24f300014ff87ba upstream.
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>
Cc: "Limonciello, Mario" <mario.limonciello@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/gpu/drm/amd/display/dc')
-rw-r--r-- | drivers/gpu/drm/amd/display/dc/dsc/dc_dsc.c | 7 |
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 3966845c7694..230be292ff35 100644 --- a/drivers/gpu/drm/amd/display/dc/dsc/dc_dsc.c +++ b/drivers/gpu/drm/amd/display/dc/dsc/dc_dsc.c @@ -1033,7 +1033,12 @@ 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( |