On 04/06/2026 18:35, Adrián Larumbe wrote: > When querying the properties of a BO, whether it was created in > Writeback caching mode for userspace mappings, is recorded in a Panfrost > BO's wb_mmap field. > > Reported-by: Claude <[email protected]> > Closes: https://gitlab.freedesktop.org/panfrost/linux/-/work_items/88 > Signed-off-by: Adrián Larumbe <[email protected]> > Fixes: 62eedf1ccba5 ("drm/panfrost: Add flag to map GEM object Write-Back > Cacheable")
This is a subtle change in uABI because bo->base.map_wc reflects the actual properties of the buffer. So on a coherent device this will change. But it does match the intention/documentation of the ioctl (returning the creation flags), and I don't think user space could have been usefully relying on the current behaviour. Reviewed-by: Steven Price <[email protected]> > --- > drivers/gpu/drm/panfrost/panfrost_drv.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/panfrost/panfrost_drv.c > b/drivers/gpu/drm/panfrost/panfrost_drv.c > index 3d0bdba2a474..cb8e5015847f 100644 > --- a/drivers/gpu/drm/panfrost/panfrost_drv.c > +++ b/drivers/gpu/drm/panfrost/panfrost_drv.c > @@ -659,7 +659,7 @@ static int panfrost_ioctl_query_bo_info(struct drm_device > *dev, void *data, > if (bo->is_heap) > args->create_flags |= PANFROST_BO_HEAP; > > - if (!bo->base.map_wc) > + if (bo->wb_mmap) > args->create_flags |= PANFROST_BO_WB_MMAP; > } > >
