From: Xinlei Lee xinlei.lee@mediatek.com
[ Upstream commit fa5d0a0205c34734c5b8daa77e39ac2817f63a10 ]
In the dsi_enable function, mtk_dsi_rxtx_control is to pull up the MIPI signal operation. Before dsi_disable, MIPI should also be pulled down by writing a register instead of disabling dsi.
If disable dsi without pulling the mipi signal low, the value of the register will still maintain the setting of the mipi signal being pulled high. After resume, even if the mipi signal is not pulled high, it will still be in the high state.
Fixes: 2e54c14e310f ("drm/mediatek: Add DSI sub driver")
Link: https://patchwork.kernel.org/project/linux-mediatek/patch/1653012007-11854-5... Signed-off-by: Jitao Shi jitao.shi@mediatek.com Signed-off-by: Xinlei Lee xinlei.lee@mediatek.com Reviewed-by: Rex-BC Chen rex-bc.chen@mediatek.com Signed-off-by: Chun-Kuang Hu chunkuang.hu@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- 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 3a6ee6e9ad2c..f0f523bdafb8 100644 --- a/drivers/gpu/drm/mediatek/mtk_dsi.c +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c @@ -682,6 +682,8 @@ static void mtk_dsi_poweroff(struct mtk_dsi *dsi) mtk_dsi_reset_engine(dsi); mtk_dsi_lane0_ulp_mode_enter(dsi); mtk_dsi_clk_ulp_mode_enter(dsi); + /* set the lane number as 0 to pull down mipi */ + writel(0, dsi->regs + DSI_TXRX_CTRL);
mtk_dsi_disable(dsi);