diff options
| author | Young Xiao <YangX92@hotmail.com> | 2018-12-17 12:23:03 +0000 |
|---|---|---|
| committer | Jani Nikula <jani.nikula@intel.com> | 2018-12-28 11:35:52 +0200 |
| commit | b8449c43c95b5ea40ced8824d4ddea997f77b911 (patch) | |
| tree | c8d192bf22bd498f3627690833370d04f4ce53a1 /drivers/gpu/drm/i915/intel_ddi.c | |
| parent | 6879216897b7dd4cfeaaed8e80e0374f260fc594 (diff) | |
| download | linux-b8449c43c95b5ea40ced8824d4ddea997f77b911.tar.bz2 | |
drm/i915: avoid division by zero on skl_calc_wrpll_link
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 0e005888b833 ("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
Diffstat (limited to 'drivers/gpu/drm/i915/intel_ddi.c')
| -rw-r--r-- | drivers/gpu/drm/i915/intel_ddi.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c index fdf57f451b72..2d6ed990a232 100644 --- a/drivers/gpu/drm/i915/intel_ddi.c +++ b/drivers/gpu/drm/i915/intel_ddi.c @@ -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); } |