drm/amd/display: Check if modulo is 0 before dividing.

[How & Why]
If a value of 0 is read, then this will cause a divide-by-0 panic.

Reviewed-by: Martin Leung <Martin.Leung@amd.com>
Acked-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Signed-off-by: David Galiffi <David.Galiffi@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
This commit is contained in:
David Galiffi 2022-05-03 18:30:25 -04:00 committed by Alex Deucher
parent 3f69ee66f5
commit 49947b906a

View File

@ -1101,9 +1101,12 @@ static bool get_pixel_clk_frequency_100hz(
* not be programmed equal to DPREFCLK
*/
modulo_hz = REG_READ(MODULO[inst]);
if (modulo_hz)
*pixel_clk_khz = div_u64((uint64_t)clock_hz*
clock_source->ctx->dc->clk_mgr->dprefclk_khz*10,
modulo_hz);
else
*pixel_clk_khz = 0;
} else {
/* NOTE: There is agreement with VBIOS here that MODULO is
* programmed equal to DPREFCLK, in which case PHASE will be