gbm_bo_map returns a stride for the mapping, which may differ from the
stride of the underlying BO. Drivers may implement mappings via staging
blits, returning a map of a temporary resource instead. That temporary
may have fewer stride restrictions (i.e. it isn't used for display), and
thus be more tightly packed, saving memory.
However, gbm_gralloc has a design flaw where after calling gbm_bo_map,
it asserts that the stride exactly matches the original BO's stride:
assert(stride == gbm_bo_get_stride(bo));
This is a bad assumption, as the GBM API returns a stride explicitly
precisely because it -can- differ. But, this would require significant
changes to gbm_gralloc to fix. So, to work around it, we add a driver
hack for Android-only that forces staging maps of any external BO to use
the original resource's stride.
This should fix issues with mapping cursor planes and SW media codec
uploads on Android-x86.
Closes: https://gitlab.freedesktop.org/mesa/mesa/-/issues/7974
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/22156>
a4e13063ed