I/O video memory for the framebuffer supports write-combine caching mode. Simplify the driver's code that sets up the caching mode. * Map video memory with ioremap_wc(), which automatically sets up the PAT entry with write-combine caching. * Remove the now obsolete call to devm_arch_io_reserve_memtype_wc(). It is only required to mmap the video memory to user space, which the driver doesn't do. * According to the PAT documentation, arch_phys_wc_add() is best called after remapping I/O memory, so move it after ioremap. Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx> --- drivers/gpu/drm/mgag200/mgag200_drv.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/mgag200/mgag200_drv.c b/drivers/gpu/drm/mgag200/mgag200_drv.c index 2fb18b782b05..54fce00e2136 100644 --- a/drivers/gpu/drm/mgag200/mgag200_drv.c +++ b/drivers/gpu/drm/mgag200/mgag200_drv.c @@ -146,14 +146,13 @@ int mgag200_device_preinit(struct mga_device *mdev) } mdev->vram_res = res; - /* Don't fail on errors, but performance might be reduced. */ - devm_arch_io_reserve_memtype_wc(dev->dev, res->start, resource_size(res)); - devm_arch_phys_wc_add(dev->dev, res->start, resource_size(res)); - - mdev->vram = devm_ioremap(dev->dev, res->start, resource_size(res)); + mdev->vram = devm_ioremap_wc(dev->dev, res->start, resource_size(res)); if (!mdev->vram) return -ENOMEM; + /* Don't fail on errors, but performance might be reduced. */ + devm_arch_phys_wc_add(dev->dev, res->start, resource_size(res)); + return 0; } -- 2.43.0
