On Fri, 2025-01-10 at 14:31 +0100, Alexandre Mergnat wrote: > External email : Please do not click links or open attachments until you have verified the sender or the content. > > > Currently, mtk_dsi_lane_ready (which setup the DSI lane) is triggered > before mtk_dsi_poweron. lanes_ready flag toggle to true during > mtk_dsi_lane_ready function, and the DSI module is set up during > mtk_dsi_poweron. > > Later, during panel driver init, mtk_dsi_lane_ready is triggered but does > nothing because lanes are considered ready. Unfortunately, when the panel > driver try to communicate, the DSI returns a timeout. > > The solution found here is to put lanes_ready flag to false after the DSI > module setup into mtk_dsi_poweron to init the DSI lanes after the power / > setup of the DSI module. I'm not clear about what happen. I think this DSI flow has worked for a long time. So only some panel has problem? And another question. Do you mean mtk_dsi_lane_ready() do some setting to hardware, but lane is not actually ready? Or mtk_dsi_lane_ready() configure the hardware and lane is is actually ready, but something make it not ready again, what's the thing which break lane ready? If this is a bug fix, add Fixes tag. Regards, CK > > Signed-off-by: Alexandre Mergnat <amergnat@xxxxxxxxxxxx> > --- > drivers/gpu/drm/mediatek/mtk_dsi.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c > index e61b9bc68e9a..dcf0d93881b5 100644 > --- a/drivers/gpu/drm/mediatek/mtk_dsi.c > +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c > @@ -724,6 +724,8 @@ static int mtk_dsi_poweron(struct mtk_dsi *dsi) > mtk_dsi_config_vdo_timing(dsi); > mtk_dsi_set_interrupt_enable(dsi); > > + dsi->lanes_ready = false; > + > return 0; > err_disable_engine_clk: > clk_disable_unprepare(dsi->engine_clk); > > -- > 2.25.1 >
