leandrof/linux
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

drm/i915: avoid division by zero on skl_calc_wrpll_link

Browse Source 
If for some unexpected reason the registers all read zero it's better
to WARN and return instead of dividing by zero and completely freezing
the machine.

See commit 0e005888b8 ("drm/i915: avoid division by zero on
cnl_calc_wrpll_link") for detail.

Signed-off-by: Young Xiao <YangX92@hotmail.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/SG2PR01MB2169F6E95BC8BB5E29477042ADBC0@SG2PR01MB2169.apcprd01.prod.exchangelabs.com
This commit is contained in:
Young Xiao 2018-12-17 12:23:03 +00:00 committed by Jani Nikula
parent 6879216897
commit b8449c43c9
1 changed files with 3 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
drivers/gpu/drm/i915/intel_ddi.c
View File

@ -1296,6 +1296,9 @@ static int skl_calc_wrpll_link(struct drm_i915_private *dev_priv,
dco_freq += (((cfgcr1_val & DPLL_CFGCR1_DCO_FRACTION_MASK) >> 9) * 24 *
1000) / 0x8000;
if (WARN_ON(p0 == 0 || p1 == 0 || p2 == 0))
return 0;
return dco_freq / (p0 * p1 * p2 * 5);
}