| commit | b18c1bb48eb5911bf99fbc5bf6509d4ae06feb9d | |
| author | Chris Wilson <chris@chris-wilson.co.uk> | |
| Tue, 6 Sep 2016 14:45:38 +0000 (6 15:45 +0100) | ||
| committer | Chris Wilson <chris@chris-wilson.co.uk> | |
| Tue, 6 Sep 2016 16:51:01 +0000 (6 17:51 +0100) | ||
| tree | 9879390f0cb3a47a8135dfcece57f312b4522b9d | treesnapshot (tar.gz zip) |
| parent | e320d40022128845dfff900422ea9fd69f576c98 | commitdiff |
drm/i915: Remove 64b mmio write vfuncs
We don't have safe 64-bit mmio writes as they are really split into
2x32-bit writes. This tearing is dangerous as the hardware *will*
operate on the intermediate value, requiring great care when assigning.
(See, for example, i965_write_fence_reg.) As such we don't currently use
them and strongly advise not to us them. Go one step further and remove
the 64-bit write vfuncs.
v2: Add some more details to the comment about why WRITE64 is absent,
and why you need to think twice before using READ64.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160906144538.4204-1-chris@chris-wilson.co.uk
We don't have safe 64-bit mmio writes as they are really split into
2x32-bit writes. This tearing is dangerous as the hardware *will*
operate on the intermediate value, requiring great care when assigning.
(See, for example, i965_write_fence_reg.) As such we don't currently use
them and strongly advise not to us them. Go one step further and remove
the 64-bit write vfuncs.
v2: Add some more details to the comment about why WRITE64 is absent,
and why you need to think twice before using READ64.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20160906144538.4204-1-chris@chris-wilson.co.uk
| drivers/gpu/drm/i915/i915_drv.h | diffblobblamehistory | |
| drivers/gpu/drm/i915/intel_uncore.c | diffblobblamehistory |