drm/i915: Add comments to explain the BSD tail write workaround
Having had to dive into the bspec to understand what each stage of the
workaround meant, and how that the ring broadcasting IDLE corresponded
with the GT powering down the ring (i.e. rc6) add comments to aide
the next reader.
And since the register "is used to control all aspects of PSMI and power
saving functions" that makes it quite interesting to inspect with
regards to RC6 hangs, so add it to the error-state.
v2: Rediscover the piece of magic, set the RNCID to 0 before waiting for
the ring to wake up.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index ac5688e..7aa6e97 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -690,10 +690,10 @@
#define GEN6_BLITTER_FBC_NOTIFY (1<<3)
#define GEN6_BSD_SLEEP_PSMI_CONTROL 0x12050
-#define GEN6_BSD_SLEEP_PSMI_CONTROL_RC_ILDL_MESSAGE_MODIFY_MASK (1 << 16)
-#define GEN6_BSD_SLEEP_PSMI_CONTROL_RC_ILDL_MESSAGE_DISABLE (1 << 0)
-#define GEN6_BSD_SLEEP_PSMI_CONTROL_RC_ILDL_MESSAGE_ENABLE 0
-#define GEN6_BSD_SLEEP_PSMI_CONTROL_IDLE_INDICATOR (1 << 3)
+#define GEN6_BSD_SLEEP_MSG_DISABLE (1 << 0)
+#define GEN6_BSD_SLEEP_FLUSH_DISABLE (1 << 2)
+#define GEN6_BSD_SLEEP_INDICATOR (1 << 3)
+#define GEN6_BSD_GO_INDICATOR (1 << 4)
#define GEN6_BSD_HWSTAM 0x12098
#define GEN6_BSD_IMR 0x120a8