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| author | Mika Kuoppala <mika.kuoppala@linux.intel.com> | 2018-05-08 15:41:54 +0300 |
|---|---|---|
| committer | Mika Kuoppala <mika.kuoppala@linux.intel.com> | 2018-05-11 15:52:21 +0300 |
| commit | ca6acc25250a1dc101c5a541b4f58bcc1dd65de5 (patch) | |
| tree | 5ea00e7451e98bc76727396ac843610d33d1d6b0 /drivers/gpu/drm/i915/intel_uncore.c | |
| parent | 429204f1059909245d8f73b66aa729c6c2807cae (diff) | |
| download | linux-ca6acc25250a1dc101c5a541b4f58bcc1dd65de5.tar.xz | |
drm/i915/gtt: Trust the uncached store to flush wcb
Not all architectures guarantee that uncached read will
flush the write combining buffer. So marking it explicitly
is recommended [1].
However we know the architecture we are operating on
and can avoid wmb as the UC store will flush the wcb [2].
Omit the wmb() before invalidate as redudant.
v2: squash combining and removal (Chris)
v3: remove obsolete comments about posting reads (Chris)
References: http://yarchive.net/comp/linux/write_combining.html [1]
References: http://download.intel.com/design/PentiumII/applnots/24442201.pdf [2]
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.auld@intel.com>
Signed-off-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20180508124154.14586-1-mika.kuoppala@linux.intel.com
Diffstat (limited to 'drivers/gpu/drm/i915/intel_uncore.c')
0 files changed, 0 insertions, 0 deletions