Hi, Hsin-yi: Hsin-Yi Wang <hsinyi@xxxxxxxxxxxx> 於 2021年7月12日 週一 下午5:47寫道： > > atomic_get_output_bus_fmts() is only called when the bridge is the last > element in the bridge chain. > > If mtk-dpi is not the last bridge, the format of output_bus_cfg is > MEDIA_BUS_FMT_FIXED, and mtk_dpi_dual_edge() will fail to write correct > value to regs. Applied to mediatek-drm-fixes [1], thanks. [1] https://git.kernel.org/pub/scm/linux/kernel/git/chunkuang.hu/linux.git/log/?h=mediatek-drm-fixes Regards, Chun-Kuang. > > Fixes: ec8747c52434 ("drm/mediatek: dpi: Add bus format negotiation") > Signed-off-by: Hsin-Yi Wang <hsinyi@xxxxxxxxxxxx> > --- > drivers/gpu/drm/mediatek/mtk_dpi.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c b/drivers/gpu/drm/mediatek/mtk_dpi.c > index bced555648b01..25c565f9179cc 100644 > --- a/drivers/gpu/drm/mediatek/mtk_dpi.c > +++ b/drivers/gpu/drm/mediatek/mtk_dpi.c > @@ -610,6 +610,10 @@ static int mtk_dpi_bridge_atomic_check(struct drm_bridge *bridge, > > out_bus_format = bridge_state->output_bus_cfg.format; > > + if (out_bus_format == MEDIA_BUS_FMT_FIXED) > + if (dpi->conf->num_output_fmts) > + out_bus_format = dpi->conf->output_fmts[0]; > + > dev_dbg(dpi->dev, "input format 0x%04x, output format 0x%04x\n", > bridge_state->input_bus_cfg.format, > bridge_state->output_bus_cfg.format); > -- > 2.32.0.93.g670b81a890-goog >
