From 39fb50f6178d7dbd70142b25193d722ebf3f8193 Mon Sep 17 00:00:00 2001 From: Eugeni Dodonov Date: Fri, 8 Jun 2012 16:43:19 -0300 Subject: [PATCH] drm/i915: properly wait for SBI status Somehow this went unnoticed in the past reviews, but the condition would never timeout properly. This was initially introduced in the v2 of original SBI enabling patch. Highly embarrassing. Note that we now actually time out for the read, which resulted in gcc complaining that we can now return unitialized garbage if that happens. There's not much we can do here because there's not much point in thread -EIO all the way down through these functions. Hence simply shut up the compiler. Reported-by: Dan Carpenter Signed-off-by: Eugeni Dodonov [danvet: Added note and squashed uninitialized value shut-up into this patch.] Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/intel_display.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 308e1a2967e7..97301621f48a 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -1350,7 +1350,7 @@ intel_sbi_write(struct drm_i915_private *dev_priv, u16 reg, u32 value) unsigned long flags; spin_lock_irqsave(&dev_priv->dpio_lock, flags); - if (wait_for((I915_READ(SBI_CTL_STAT) & SBI_READY) == 0, + if (wait_for((I915_READ(SBI_CTL_STAT) & SBI_BUSY) == 0, 100)) { DRM_ERROR("timeout waiting for SBI to become ready\n"); goto out_unlock; @@ -1364,7 +1364,7 @@ intel_sbi_write(struct drm_i915_private *dev_priv, u16 reg, u32 value) SBI_BUSY | SBI_CTL_OP_CRWR); - if (wait_for((I915_READ(SBI_CTL_STAT) & (SBI_READY | SBI_RESPONSE_SUCCESS)) == 0, + if (wait_for((I915_READ(SBI_CTL_STAT) & (SBI_BUSY | SBI_RESPONSE_FAIL)) == 0, 100)) { DRM_ERROR("timeout waiting for SBI to complete write transaction\n"); goto out_unlock; @@ -1378,10 +1378,10 @@ static u32 intel_sbi_read(struct drm_i915_private *dev_priv, u16 reg) { unsigned long flags; - u32 value; + u32 value = 0; spin_lock_irqsave(&dev_priv->dpio_lock, flags); - if (wait_for((I915_READ(SBI_CTL_STAT) & SBI_READY) == 0, + if (wait_for((I915_READ(SBI_CTL_STAT) & SBI_BUSY) == 0, 100)) { DRM_ERROR("timeout waiting for SBI to become ready\n"); goto out_unlock; @@ -1393,7 +1393,7 @@ intel_sbi_read(struct drm_i915_private *dev_priv, u16 reg) SBI_BUSY | SBI_CTL_OP_CRRD); - if (wait_for((I915_READ(SBI_CTL_STAT) & (SBI_READY | SBI_RESPONSE_SUCCESS)) == 0, + if (wait_for((I915_READ(SBI_CTL_STAT) & (SBI_BUSY | SBI_RESPONSE_FAIL)) == 0, 100)) { DRM_ERROR("timeout waiting for SBI to complete read transaction\n"); goto out_unlock; -- 2.20.1