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| author | Chris Wilson <chris@chris-wilson.co.uk> | 2011-03-04 22:22:40 +0300 |
|---|---|---|
| committer | Chris Wilson <chris@chris-wilson.co.uk> | 2011-03-06 12:07:46 +0300 |
| commit | 91355834646328e7edc6bd25176ae44bcd7386c7 (patch) | |
| tree | 24539f6a0d2ba30f5973a78d7a639f6ce140091d /drivers/gpu/drm/i915/i915_reg.h | |
| parent | 0ee537abbd10a9abf11e1c22ee32a68e8c12ed4a (diff) | |
| download | linux-91355834646328e7edc6bd25176ae44bcd7386c7.tar.xz | |
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>
Diffstat (limited to 'drivers/gpu/drm/i915/i915_reg.h')
| -rw-r--r-- | drivers/gpu/drm/i915/i915_reg.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h index 729d4233b763..3e6f486f4605 100644 --- a/drivers/gpu/drm/i915/i915_reg.h +++ b/drivers/gpu/drm/i915/i915_reg.h @@ -3261,6 +3261,8 @@ #define FORCEWAKE 0xA18C #define FORCEWAKE_ACK 0x130090 +#define GT_FIFO_FREE_ENTRIES 0x120008 + #define GEN6_RPNSWREQ 0xA008 #define GEN6_TURBO_DISABLE (1<<31) #define GEN6_FREQUENCY(x) ((x)<<25) |