drm/i915: Capture ERROR register on Sandybridge hangs

This holds error state from the main graphics arbiter mainly involving
the DMA engine and address translation.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

4 files changed, 17 insertions, 7 deletions

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 2e5961139326..4fc1e05b769f 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -615,6 +615,9 @@ static int i915_error_state(struct seq_file *m, void *unused)
         seq_printf(m, "Time: %ld s %ld us\n", error->time.tv_sec,
                    error->time.tv_usec);
         seq_printf(m, "PCI ID: 0x%04x\n", dev->pci_device);
+        if (INTEL_INFO(dev)->gen >= 6) {
+                seq_printf(m, "ERROR: 0x%08x\n", error->error);
+        }
         seq_printf(m, "EIR: 0x%08x\n", error->eir);
         seq_printf(m, "  PGTBL_ER: 0x%08x\n", error->pgtbl_er);
         seq_printf(m, "  INSTPM: 0x%08x\n", error->instpm);
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index cdae5d189165..895f9173de58 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -142,6 +142,7 @@ struct sdvo_device_mapping {
 struct drm_i915_error_state {
         u32 eir;
         u32 pgtbl_er;
+        u32 error; /* gen6+ */
         u32 pipeastat;
         u32 pipebstat;
         u32 ipeir;
diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 29cbcb33b92c..2a29497a4694 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -592,13 +592,11 @@ static void i915_capture_error_state(struct drm_device *dev)
         error->pipeastat = I915_READ(PIPEASTAT);
         error->pipebstat = I915_READ(PIPEBSTAT);
         error->instpm = I915_READ(INSTPM);
-        if (INTEL_INFO(dev)->gen < 4) {
-                error->ipeir = I915_READ(IPEIR);
-                error->ipehr = I915_READ(IPEHR);
-                error->instdone = I915_READ(INSTDONE);
-                error->acthd = I915_READ(ACTHD);
-                error->bbaddr = 0;
-        } else {
+        error->error = 0;
+        if (INTEL_INFO(dev)->gen >= 6) {
+                error->error = I915_READ(ERROR_GEN6);
+        }
+        if (INTEL_INFO(dev)->gen >= 4) {
                 error->ipeir = I915_READ(IPEIR_I965);
                 error->ipehr = I915_READ(IPEHR_I965);
                 error->instdone = I915_READ(INSTDONE_I965);
@@ -606,6 +604,12 @@ static void i915_capture_error_state(struct drm_device *dev)
                 error->instdone1 = I915_READ(INSTDONE1);
                 error->acthd = I915_READ(ACTHD_I965);
                 error->bbaddr = I915_READ64(BB_ADDR);
+        } else {
+                error->ipeir = I915_READ(IPEIR);
+                error->ipehr = I915_READ(IPEHR);
+                error->instdone = I915_READ(INSTDONE);
+                error->acthd = I915_READ(ACTHD);
+                error->bbaddr = 0;
         }
 
         bbaddr = i915_ringbuffer_last_batch(dev);
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 25ed911a3112..fc161196da21 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -306,6 +306,8 @@
 #define NOPID           0x02094
 #define HWSTAM          0x02098
 
+#define ERROR_GEN6      0x040a0
+
 #define MI_MODE         0x0209c
 # define VS_TIMER_DISPATCH                              (1 << 6)
 # define MI_FLUSH_ENABLE                                (1 << 11)