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authorVille Syrjälä <[email protected]>2013-12-02 19:00:45 +0200
committerDaniel Vetter <[email protected]>2013-12-03 18:02:01 +0100
commited5ca77ed7505cd389003a6d35ca1b7365429d71 (patch)
tree2783065802046fd7809706e3a170155749613edf
parent7e11f9f4cacf71847716cec9d103b25d4c21e7a0 (diff)
drm/i915: Avoid div-by-zero in clock calculation funcs
Check that the N and P dividers don't cause a divide by zero. This shouldn't happen under normal circumstances, but can happen eg. under simulation. Signed-off-by: Ville Syrjälä <[email protected]> Reviewed-by: Jesse Barnes <[email protected]> Signed-off-by: Daniel Vetter <[email protected]>
-rw-r--r--drivers/gpu/drm/i915/intel_display.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 0332d7ca892d..66b39dbaf12c 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -329,6 +329,8 @@ static void vlv_clock(int refclk, intel_clock_t *clock)
{
clock->m = clock->m1 * clock->m2;
clock->p = clock->p1 * clock->p2;
+ if (WARN_ON(clock->n == 0 || clock->p == 0))
+ return;
clock->vco = DIV_ROUND_CLOSEST(refclk * clock->m, clock->n);
clock->dot = DIV_ROUND_CLOSEST(clock->vco, clock->p);
}
@@ -430,6 +432,8 @@ static void pineview_clock(int refclk, intel_clock_t *clock)
{
clock->m = clock->m2 + 2;
clock->p = clock->p1 * clock->p2;
+ if (WARN_ON(clock->n == 0 || clock->p == 0))
+ return;
clock->vco = DIV_ROUND_CLOSEST(refclk * clock->m, clock->n);
clock->dot = DIV_ROUND_CLOSEST(clock->vco, clock->p);
}
@@ -443,6 +447,8 @@ static void i9xx_clock(int refclk, intel_clock_t *clock)
{
clock->m = i9xx_dpll_compute_m(clock);
clock->p = clock->p1 * clock->p2;
+ if (WARN_ON(clock->n + 2 == 0 || clock->p == 0))
+ return;
clock->vco = DIV_ROUND_CLOSEST(refclk * clock->m, clock->n + 2);
clock->dot = DIV_ROUND_CLOSEST(clock->vco, clock->p);
}