diff options
| -rw-r--r-- | drivers/gpu/drm/sun4i/sun4i_backend.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/drivers/gpu/drm/sun4i/sun4i_backend.c b/drivers/gpu/drm/sun4i/sun4i_backend.c index 243ddfdc9403..4fefd8add714 100644 --- a/drivers/gpu/drm/sun4i/sun4i_backend.c +++ b/drivers/gpu/drm/sun4i/sun4i_backend.c @@ -412,7 +412,14 @@ static int sun4i_backend_bind(struct device *dev, struct device *master, list_add_tail(&backend->engine.list, &drv->engine_list); - /* Reset the registers */ + /* + * Many of the backend's layer configuration registers have + * undefined default values. This poses a risk as we use + * regmap_update_bits in some places, and don't overwrite + * the whole register. + * + * Clear the registers here to have something predictable. + */ for (i = 0x800; i < 0x1000; i += 4) regmap_write(backend->engine.regs, i, 0); |