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authorChris Wilson <chris@chris-wilson.co.uk>2017-02-23 14:10:20 +0000
committerChris Wilson <chris@chris-wilson.co.uk>2017-02-27 17:22:19 +0000
commitb0734f77b3d1ae00603bf478611662d5bf6c9b54 (patch)
treef091ade81021b5987203709f53020e8c315d6a78
parentafeddf50811253ee512fb9192cfb443891929776 (diff)
downloadlwn-b0734f77b3d1ae00603bf478611662d5bf6c9b54.tar.gz
lwn-b0734f77b3d1ae00603bf478611662d5bf6c9b54.zip
drm/i915: Distinguish between timeout and error in sideband transactions
After initiating a sideband transaction, we only want to wait for the transaction to become idle. If, as we are, we wait for both the busy and error flag to clear, if an error is raised we just spin until the timeout. Once the hw is idle, we can then check to see if the hw flagged an error, and report it distinctly. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Jani Nikula <jani.nikula@intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/20170223141020.13250-1-chris@chris-wilson.co.uk Reviewed-by: Jani Nikula <jani.nikula@intel.com>
-rw-r--r--drivers/gpu/drm/i915/intel_sideband.c20
1 files changed, 16 insertions, 4 deletions
diff --git a/drivers/gpu/drm/i915/intel_sideband.c b/drivers/gpu/drm/i915/intel_sideband.c
index 9f782b5eb6e6..7d971cb56116 100644
--- a/drivers/gpu/drm/i915/intel_sideband.c
+++ b/drivers/gpu/drm/i915/intel_sideband.c
@@ -216,6 +216,7 @@ u32 intel_sbi_read(struct drm_i915_private *dev_priv, u16 reg,
}
I915_WRITE(SBI_ADDR, (reg << 16));
+ I915_WRITE(SBI_DATA, 0);
if (destination == SBI_ICLK)
value = SBI_CTL_DEST_ICLK | SBI_CTL_OP_CRRD;
@@ -225,10 +226,15 @@ u32 intel_sbi_read(struct drm_i915_private *dev_priv, u16 reg,
if (intel_wait_for_register(dev_priv,
SBI_CTL_STAT,
- SBI_BUSY | SBI_RESPONSE_FAIL,
+ SBI_BUSY,
0,
100)) {
- DRM_ERROR("timeout waiting for SBI to complete read transaction\n");
+ DRM_ERROR("timeout waiting for SBI to complete read\n");
+ return 0;
+ }
+
+ if (I915_READ(SBI_CTL_STAT) & SBI_RESPONSE_FAIL) {
+ DRM_ERROR("error during SBI read of reg %x\n", reg);
return 0;
}
@@ -260,10 +266,16 @@ void intel_sbi_write(struct drm_i915_private *dev_priv, u16 reg, u32 value,
if (intel_wait_for_register(dev_priv,
SBI_CTL_STAT,
- SBI_BUSY | SBI_RESPONSE_FAIL,
+ SBI_BUSY,
0,
100)) {
- DRM_ERROR("timeout waiting for SBI to complete write transaction\n");
+ DRM_ERROR("timeout waiting for SBI to complete write\n");
+ return;
+ }
+
+ if (I915_READ(SBI_CTL_STAT) & SBI_RESPONSE_FAIL) {
+ DRM_ERROR("error during SBI write of %x to reg %x\n",
+ value, reg);
return;
}
}