From ed5ca77ed7505cd389003a6d35ca1b7365429d71 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Ville=20Syrj=C3=A4l=C3=A4?= Date: Mon, 2 Dec 2013 19:00:45 +0200 Subject: [PATCH] drm/i915: Avoid div-by-zero in clock calculation funcs MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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 Reviewed-by: Jesse Barnes Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/intel_display.c | 6 ++++++ 1 file changed, 6 insertions(+) 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); } -- 2.11.0