drm/i915: Do not overflow the MMADDR write FIFO
Whilst the GT is powered down (rc6), writes to MMADDR are placed in a
FIFO by the System Agent. This is a limited resource, only 64 entries, of
which 20 are reserved for Display and PCH writes, and so we must take
care not to queue up too many writes. To avoid this, there is counter
which we can poll to ensure there are sufficient free entries in the
fifo.
"Issuing a write to a full FIFO is not supported; at worst it could
result in corruption or a system hang."
Reported-and-Tested-by: Matt Turner <mattst88@gmail.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=34056
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index e79b25b..49fb54f 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -1219,7 +1219,7 @@
u32 blt_ecoskpd;
/* Make sure blitter notifies FBC of writes */
- __gen6_force_wake_get(dev_priv);
+ __gen6_gt_force_wake_get(dev_priv);
blt_ecoskpd = I915_READ(GEN6_BLITTER_ECOSKPD);
blt_ecoskpd |= GEN6_BLITTER_FBC_NOTIFY <<
GEN6_BLITTER_LOCK_SHIFT;
@@ -1230,7 +1230,7 @@
GEN6_BLITTER_LOCK_SHIFT);
I915_WRITE(GEN6_BLITTER_ECOSKPD, blt_ecoskpd);
POSTING_READ(GEN6_BLITTER_ECOSKPD);
- __gen6_force_wake_put(dev_priv);
+ __gen6_gt_force_wake_put(dev_priv);
}
static void ironlake_enable_fbc(struct drm_crtc *crtc, unsigned long interval)
@@ -6282,7 +6282,7 @@
* userspace...
*/
I915_WRITE(GEN6_RC_STATE, 0);
- __gen6_force_wake_get(dev_priv);
+ __gen6_gt_force_wake_get(dev_priv);
/* disable the counters and set deterministic thresholds */
I915_WRITE(GEN6_RC_CONTROL, 0);
@@ -6380,7 +6380,7 @@
/* enable all PM interrupts */
I915_WRITE(GEN6_PMINTRMSK, 0);
- __gen6_force_wake_put(dev_priv);
+ __gen6_gt_force_wake_put(dev_priv);
}
void intel_enable_clock_gating(struct drm_device *dev)