From 5190707e7a4fc701e94cd7e152d15dbba90b63ff Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= Date: Fri, 18 Aug 2017 21:37:02 +0300 Subject: [PATCH] drm/i915: Gen3 HWSTAM is actually 32 bits MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Bspec claims that HWSTAM is only 16 bits on gen3, but the other interrupts registers are 32 bits and there are 18 valid interrupt bits. Hence a 16 bit HWSTAM wouldn't be able to contain all the bits, so it seems the spec is incorrect about the size of the register. And indeed I can clear bits 16 and 17 just fine with a 32 bit write. So let's adjust the code to treat the register as 32 bits. Acked-by: Chris Wilson Signed-off-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20170818183705.27850-14-ville.syrjala@linux.intel.com --- drivers/gpu/drm/i915/i915_irq.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c index 26569a00b40c..003a92857102 100644 --- a/drivers/gpu/drm/i915/i915_irq.c +++ b/drivers/gpu/drm/i915/i915_irq.c @@ -3755,7 +3755,7 @@ static void i915_irq_preinstall(struct drm_device * dev) i9xx_pipestat_irq_reset(dev_priv); - I915_WRITE16(HWSTAM, 0xeffe); + I915_WRITE(HWSTAM, 0xffffeffe); GEN3_IRQ_RESET(); } @@ -3862,7 +3862,7 @@ static void i915_irq_uninstall(struct drm_device * dev) i9xx_pipestat_irq_reset(dev_priv); - I915_WRITE16(HWSTAM, 0xffff); + I915_WRITE(HWSTAM, 0xffffffff); GEN3_IRQ_RESET(); } -- GitLab