From da73a94fa282f78d485bd0aab36c8ac15b6f792c Mon Sep 17 00:00:00 2001 From: Philippe Schenker Date: Thu, 22 Sep 2022 14:43:03 +0200 Subject: [PATCH 1/4] drm/bridge: lt8912b: add vsync hsync Currently the bridge driver does not take care whether or not the display needs positive/negative vertical/horizontal syncs. Pass these two flags to the bridge from the EDID that was read out from the display. Fixes: 30e2ae943c26 ("drm/bridge: Introduce LT8912B DSI to HDMI bridge") Signed-off-by: Philippe Schenker Acked-by: Adrien Grassein Signed-off-by: Neil Armstrong Link: https://patchwork.freedesktop.org/patch/msgid/20220922124306.34729-2-dev@pschenker.ch --- drivers/gpu/drm/bridge/lontium-lt8912b.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/bridge/lontium-lt8912b.c b/drivers/gpu/drm/bridge/lontium-lt8912b.c index 28bad30dc4e5..0fd3472e767c 100644 --- a/drivers/gpu/drm/bridge/lontium-lt8912b.c +++ b/drivers/gpu/drm/bridge/lontium-lt8912b.c @@ -268,7 +268,7 @@ static int lt8912_video_setup(struct lt8912 *lt) u32 hactive, h_total, hpw, hfp, hbp; u32 vactive, v_total, vpw, vfp, vbp; u8 settle = 0x08; - int ret; + int ret, hsync_activehigh, vsync_activehigh; if (!lt) return -EINVAL; @@ -278,12 +278,14 @@ static int lt8912_video_setup(struct lt8912 *lt) hpw = lt->mode.hsync_len; hbp = lt->mode.hback_porch; h_total = hactive + hfp + hpw + hbp; + hsync_activehigh = lt->mode.flags & DISPLAY_FLAGS_HSYNC_HIGH; vactive = lt->mode.vactive; vfp = lt->mode.vfront_porch; vpw = lt->mode.vsync_len; vbp = lt->mode.vback_porch; v_total = vactive + vfp + vpw + vbp; + vsync_activehigh = lt->mode.flags & DISPLAY_FLAGS_VSYNC_HIGH; if (vactive <= 600) settle = 0x04; @@ -317,6 +319,11 @@ static int lt8912_video_setup(struct lt8912 *lt) ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x3e, hfp & 0xff); ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x3f, hfp >> 8); + ret |= regmap_update_bits(lt->regmap[I2C_MAIN], 0xab, BIT(0), + vsync_activehigh ? BIT(0) : 0); + ret |= regmap_update_bits(lt->regmap[I2C_MAIN], 0xab, BIT(1), + hsync_activehigh ? BIT(1) : 0); + return ret; } From 6dd1de12e1243f2013e4fabf31e99e63b1a860d0 Mon Sep 17 00:00:00 2001 From: Philippe Schenker Date: Thu, 22 Sep 2022 14:43:04 +0200 Subject: [PATCH 2/4] drm/bridge: lt8912b: set hdmi or dvi mode The Lontium LT8912 does have a setting for DVI or HDMI. This patch reads from EDID what the display needs and sets it accordingly. Fixes: 30e2ae943c26 ("drm/bridge: Introduce LT8912B DSI to HDMI bridge") Signed-off-by: Philippe Schenker Acked-by: Adrien Grassein Signed-off-by: Neil Armstrong Link: https://patchwork.freedesktop.org/patch/msgid/20220922124306.34729-3-dev@pschenker.ch --- drivers/gpu/drm/bridge/lontium-lt8912b.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/gpu/drm/bridge/lontium-lt8912b.c b/drivers/gpu/drm/bridge/lontium-lt8912b.c index 0fd3472e767c..6a4bb7422176 100644 --- a/drivers/gpu/drm/bridge/lontium-lt8912b.c +++ b/drivers/gpu/drm/bridge/lontium-lt8912b.c @@ -323,6 +323,8 @@ static int lt8912_video_setup(struct lt8912 *lt) vsync_activehigh ? BIT(0) : 0); ret |= regmap_update_bits(lt->regmap[I2C_MAIN], 0xab, BIT(1), hsync_activehigh ? BIT(1) : 0); + ret |= regmap_update_bits(lt->regmap[I2C_MAIN], 0xb2, BIT(0), + lt->connector.display_info.is_hdmi ? BIT(0) : 0); return ret; } From 051ad2788d35ca07aec8402542e5d38429f2426a Mon Sep 17 00:00:00 2001 From: Francesco Dolcini Date: Thu, 22 Sep 2022 14:43:05 +0200 Subject: [PATCH 3/4] drm/bridge: lt8912b: fix corrupted image output Correct I2C address for the register list in lt8912_write_lvds_config(), these registers are on the first I2C address (0x48), the current function is just writing garbage to the wrong registers and this creates multiple issues (artifacts and output completely corrupted) on some HDMI displays. Correct I2C address comes from Lontium documentation and it is the one used on other out-of-tree LT8912B drivers [1]. [1] https://github.com/boundarydevices/linux/blob/boundary-imx_5.10.x_2.0.0/drivers/video/lt8912.c#L296 Fixes: 30e2ae943c26 ("drm/bridge: Introduce LT8912B DSI to HDMI bridge") Signed-off-by: Francesco Dolcini Signed-off-by: Philippe Schenker Acked-by: Adrien Grassein Signed-off-by: Neil Armstrong Link: https://patchwork.freedesktop.org/patch/msgid/20220922124306.34729-4-dev@pschenker.ch --- drivers/gpu/drm/bridge/lontium-lt8912b.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/bridge/lontium-lt8912b.c b/drivers/gpu/drm/bridge/lontium-lt8912b.c index 6a4bb7422176..5968f4af190b 100644 --- a/drivers/gpu/drm/bridge/lontium-lt8912b.c +++ b/drivers/gpu/drm/bridge/lontium-lt8912b.c @@ -188,7 +188,7 @@ static int lt8912_write_lvds_config(struct lt8912 *lt) {0x03, 0xff}, }; - return regmap_multi_reg_write(lt->regmap[I2C_CEC_DSI], seq, ARRAY_SIZE(seq)); + return regmap_multi_reg_write(lt->regmap[I2C_MAIN], seq, ARRAY_SIZE(seq)); }; static inline struct lt8912 *bridge_to_lt8912(struct drm_bridge *b) From cc62d98bd56d45de4531844ca23913a15136c05b Mon Sep 17 00:00:00 2001 From: Brian Norris Date: Mon, 22 Aug 2022 18:08:04 -0700 Subject: [PATCH 4/4] Revert "drm: bridge: analogix/dp: add panel prepare/unprepare in suspend/resume time" This reverts commit 211f276ed3d96e964d2d1106a198c7f4a4b3f4c0. For quite some time, core DRM helpers already ensure that any relevant connectors/CRTCs/etc. are disabled, as well as their associated components (e.g., bridges) when suspending the system. Thus, analogix_dp_bridge_{enable,disable}() already get called, which in turn call drm_panel_{prepare,unprepare}(). This makes these drm_panel_*() calls redundant. Besides redundancy, there are a few problems with this handling: (1) drm_panel_{prepare,unprepare}() are *not* reference-counted APIs and are not in general designed to be handled by multiple callers -- although some panel drivers have a coarse 'prepared' flag that mitigates some damage, at least. So at a minimum this is redundant and confusing, but in some cases, this could be actively harmful. (2) The error-handling is a bit non-standard. We ignored errors in suspend(), but handled errors in resume(). And recently, people noticed that the clk handling is unbalanced in error paths, and getting *that* right is not actually trivial, given the current way errors are mostly ignored. (3) In the particular way analogix_dp_{suspend,resume}() get used (e.g., in rockchip_dp_*(), as a late/early callback), we don't necessarily have a proper PM relationship between the DP/bridge device and the panel device. So while the DP bridge gets resumed, the panel's parent device (e.g., platform_device) may still be suspended, and so any prepare() calls may fail. So remove the superfluous, possibly-harmful suspend()/resume() handling of panel state. Fixes: 211f276ed3d9 ("drm: bridge: analogix/dp: add panel prepare/unprepare in suspend/resume time") Link: https://lore.kernel.org/all/Yv2CPBD3Picg%2FgVe@google.com/ Signed-off-by: Brian Norris Reviewed-by: Douglas Anderson Signed-off-by: Douglas Anderson Link: https://patchwork.freedesktop.org/patch/msgid/20220822180729.1.I8ac5abe3a4c1c6fd5c061686c6e883c22f69022c@changeid --- drivers/gpu/drm/bridge/analogix/analogix_dp_core.c | 13 ------------- 1 file changed, 13 deletions(-) diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c index 8aadcc0aa90b..df9370e0ff23 100644 --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c @@ -1864,12 +1864,6 @@ EXPORT_SYMBOL_GPL(analogix_dp_remove); int analogix_dp_suspend(struct analogix_dp_device *dp) { clk_disable_unprepare(dp->clock); - - if (dp->plat_data->panel) { - if (drm_panel_unprepare(dp->plat_data->panel)) - DRM_ERROR("failed to turnoff the panel\n"); - } - return 0; } EXPORT_SYMBOL_GPL(analogix_dp_suspend); @@ -1884,13 +1878,6 @@ int analogix_dp_resume(struct analogix_dp_device *dp) return ret; } - if (dp->plat_data->panel) { - if (drm_panel_prepare(dp->plat_data->panel)) { - DRM_ERROR("failed to setup the panel\n"); - return -EBUSY; - } - } - return 0; } EXPORT_SYMBOL_GPL(analogix_dp_resume);