Re: [PATCH] drm/mediatek: mtk_dsi: enable hs clock during pre-enable
From: Chun-Kuang Hu <chunkuang.hu@kernel.org>
Date: 2026-03-22 12:48:45
Also in:
dri-devel, linux-mediatek, lkml
Hi, Gary: Gary Bisson [off-list ref] 於 2026年1月20日週二 上午11:37寫道：
Some bridges, such as the TI SN65DSI83, require the HS clock to be running in order to lock its PLL during its own pre-enable function. Without this change, the bridge gives the following error: sn65dsi83 14-002c: failed to lock PLL, ret=-110 sn65dsi83 14-002c: Unexpected link status 0x01 sn65dsi83 14-002c: reset the pipe Move the necessary functions from enable to pre-enable.
Applied to mediatek-drm-next [1], thanks. [1] https://git.kernel.org/pub/scm/linux/kernel/git/chunkuang.hu/linux.git/log/?h=mediatek-drm-next Regards, Chun-Kuang.
quoted hunk ↗ jump to hunk
Signed-off-by: Gary Bisson <redacted> --- Tested on Tungsten510 module with sn65dsi83 + tm070jdhg30 panel. Left mtk_dsi_set_mode() as part of the enable function to mimic what is done in the Samsung DSIM driver which is known to be working the TI bridge. --- drivers/gpu/drm/mediatek/mtk_dsi.c | 35 +++++++++++++++++------------------ 1 file changed, 17 insertions(+), 18 deletions(-)diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c index 0e2bcd5f67b7..b560245d1be9 100644 --- a/drivers/gpu/drm/mediatek/mtk_dsi.c +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c@@ -672,6 +672,21 @@ static s32 mtk_dsi_switch_to_cmd_mode(struct mtk_dsi *dsi, u8 irq_flag, u32 t) } } +static void mtk_dsi_lane_ready(struct mtk_dsi *dsi) +{ + if (!dsi->lanes_ready) { + dsi->lanes_ready = true; + mtk_dsi_rxtx_control(dsi); + usleep_range(30, 100); + mtk_dsi_reset_dphy(dsi); + mtk_dsi_clk_ulp_mode_leave(dsi); + mtk_dsi_lane0_ulp_mode_leave(dsi); + mtk_dsi_clk_hs_mode(dsi, 0); + usleep_range(1000, 3000); + /* The reaction time after pulling up the mipi signal for dsi_rx */ + } +} + static int mtk_dsi_poweron(struct mtk_dsi *dsi) { struct device *dev = dsi->host.dev;@@ -724,6 +739,8 @@ static int mtk_dsi_poweron(struct mtk_dsi *dsi) mtk_dsi_set_vm_cmd(dsi); mtk_dsi_config_vdo_timing(dsi); mtk_dsi_set_interrupt_enable(dsi); + mtk_dsi_lane_ready(dsi); + mtk_dsi_clk_hs_mode(dsi, 1); return 0; err_disable_engine_clk:@@ -769,30 +786,12 @@ static void mtk_dsi_poweroff(struct mtk_dsi *dsi) dsi->lanes_ready = false; } -static void mtk_dsi_lane_ready(struct mtk_dsi *dsi) -{ - if (!dsi->lanes_ready) { - dsi->lanes_ready = true; - mtk_dsi_rxtx_control(dsi); - usleep_range(30, 100); - mtk_dsi_reset_dphy(dsi); - mtk_dsi_clk_ulp_mode_leave(dsi); - mtk_dsi_lane0_ulp_mode_leave(dsi); - mtk_dsi_clk_hs_mode(dsi, 0); - usleep_range(1000, 3000); - /* The reaction time after pulling up the mipi signal for dsi_rx */ - } -} - static void mtk_output_dsi_enable(struct mtk_dsi *dsi) { if (dsi->enabled) return; - mtk_dsi_lane_ready(dsi); mtk_dsi_set_mode(dsi); - mtk_dsi_clk_hs_mode(dsi, 1); - mtk_dsi_start(dsi); dsi->enabled = true;--- base-commit: 8f0b4cce4481fb22653697cced8d0d04027cb1e8 change-id: 20260120-mtkdsi-29e4c84e7b38 Best regards, -- Gary Bisson [off-list ref]