From 2a2430f4542467502d39660bfd66b0004fd8d6a9 Mon Sep 17 00:00:00 2001 From: Jesse Barnes Date: Thu, 16 Jul 2009 13:01:02 -0700 Subject: [PATCH] drm/i915: correct self-refresh calculation in "everything off" case If no planes are enabled, the self-refresh calculation may end up doing a divide by zero. This patch should prevent that by making sure at least one of the CRTCs had a valid hdisplay value. Reported-by: Eric Anholt Tested-by: Eric Anholt Signed-off-by: Jesse Barnes Signed-off-by: Eric Anholt --- drivers/gpu/drm/i915/intel_display.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 890f7108e723..a58bfadabd6f 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -1906,7 +1906,7 @@ static void i9xx_update_wm(struct drm_device *dev, int planea_clock, cwm = 2; /* Calc sr entries for one plane configs */ - if (!planea_clock || !planeb_clock) { + if (sr_hdisplay && (!planea_clock || !planeb_clock)) { /* self-refresh has much higher latency */ const static int sr_latency_ns = 6000; @@ -1921,6 +1921,8 @@ static void i9xx_update_wm(struct drm_device *dev, int planea_clock, srwm = total_size - sr_entries; if (srwm < 0) srwm = 1; + if (IS_I9XX(dev)) + I915_WRITE(FW_BLC_SELF, (srwm & 0x3f)); } DRM_DEBUG("Setting FIFO watermarks - A: %d, B: %d, C: %d, SR %d\n", @@ -1935,8 +1937,6 @@ static void i9xx_update_wm(struct drm_device *dev, int planea_clock, I915_WRITE(FW_BLC, fwater_lo); I915_WRITE(FW_BLC2, fwater_hi); - if (IS_I9XX(dev)) - I915_WRITE(FW_BLC_SELF, (srwm & 0x3f)); } static void i830_update_wm(struct drm_device *dev, int planea_clock, -- 2.11.0