On Mon, 2 Dec 2013 19:00:45 +0200
ville.syrjala@xxxxxxxxxxxxxxx wrote:
> From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
>
> 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 <ville.syrjala@xxxxxxxxxxxxxxx>
> ---
> 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 0bb3d6d..4bedaf9 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);
> }
Reviewed-by: Jesse Barnes <jbarnes@xxxxxxxxxxxxxxxx>
--
Jesse Barnes, Intel Open Source Technology Center
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