From 7e79a6836cfd1bac20e2be3fafdc3caca27c9d69 Mon Sep 17 00:00:00 2001 From: Sagar Arun Kamble Date: Fri, 20 Jan 2017 09:18:24 +0530 Subject: [PATCH] drm/i915: Set adjustment to zero on Up/Down interrupts if freq is already max/min When we reach the user's RPS limits, stop requesting an adjustment. Even though we will clamp the requested frequency later, we rely on interrupt masking to disable further adjustments in the same direction. Even though it is unlikely (one scenario is a bug in the driver, another is careful manipulation through the uAPI) if we keep exponentially increasing the adjustment value, it will wrap and cause a negative adjustment. Signed-off-by: Chris Wilson Reviewed-by: Sagar Arun Kamble Link: http://patchwork.freedesktop.org/patch/msgid/1484884104-28134-2-git-send-email-sagar.a.kamble@intel.com --- drivers/gpu/drm/i915/i915_irq.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c index ce5663d..6fefc34 100644 --- a/drivers/gpu/drm/i915/i915_irq.c +++ b/drivers/gpu/drm/i915/i915_irq.c @@ -1170,6 +1170,9 @@ static void gen6_pm_rps_work(struct work_struct *work) adj *= 2; else /* CHV needs even encode values */ adj = IS_CHERRYVIEW(dev_priv) ? 2 : 1; + + if (new_delay >= dev_priv->rps.max_freq_softlimit) + adj = 0; /* * For better performance, jump directly * to RPe if we're below it. @@ -1191,6 +1194,9 @@ static void gen6_pm_rps_work(struct work_struct *work) adj *= 2; else /* CHV needs even encode values */ adj = IS_CHERRYVIEW(dev_priv) ? -2 : -1; + + if (new_delay <= dev_priv->rps.min_freq_softlimit) + adj = 0; } else { /* unknown event */ adj = 0; } -- 2.7.4