On Sa, 2022-04-16 at 10:07 +0800, Nancy.Lin wrote: > Add merge async reset control in mtk_merge_stop. Async hw doesn't do self > reset on each sof signal(start of frame), so need to reset the async to > clear the hw status for the next merge start. > > Signed-off-by: Nancy.Lin <nancy.lin@xxxxxxxxxxxx> > Reviewed-by: CK Hu <ck.hu@xxxxxxxxxxxx> > Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx> > --- > drivers/gpu/drm/mediatek/mtk_disp_merge.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/gpu/drm/mediatek/mtk_disp_merge.c b/drivers/gpu/drm/mediatek/mtk_disp_merge.c > index 9dca145cfb71..177473fa8160 100644 > --- a/drivers/gpu/drm/mediatek/mtk_disp_merge.c > +++ b/drivers/gpu/drm/mediatek/mtk_disp_merge.c > @@ -8,6 +8,7 @@ > #include <linux/of_device.h> > #include <linux/of_irq.h> > #include <linux/platform_device.h> > +#include <linux/reset.h> > #include <linux/soc/mediatek/mtk-cmdq.h> > > > > > #include "mtk_drm_ddp_comp.h" > @@ -79,6 +80,9 @@ void mtk_merge_stop(struct device *dev) > struct mtk_disp_merge *priv = dev_get_drvdata(dev); > > > > > mtk_merge_stop_cmdq(dev, NULL); > + > + if (priv->async_clk) > + device_reset_optional(dev); To avoid the overhead of looking up the reset control in the device tree every time, it would be better to request a reset control during probe using devm_reset_control_get_optional_exclusive(). Here you'd just call reset_control_reset(). regards Philipp
