From: Loic Poulain Date: Wed, 9 Jul 2025 14:08:36 +0000 (+0200) Subject: drm/msm/dsi: Fix 14nm DSI PHY PLL Lock issue X-Git-Tag: v6.17-rc4~14^2~1^2~14 X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=0b3ccb76b95bd06cf80124d8adda647c82a6cc0f;p=users%2Fgriffoul%2Flinux.git drm/msm/dsi: Fix 14nm DSI PHY PLL Lock issue To configure and enable the DSI PHY PLL clocks, the MDSS AHB clock must be active for MMIO operations. Typically, this AHB clock is enabled as part of the DSI PHY interface enabling (dsi_phy_enable_resource). However, since these PLL clocks are registered as clock entities, they can be enabled independently of the DSI PHY interface, leading to enabling failures and subsequent warnings: ``` msm_dsi_phy 5e94400.phy: [drm:dsi_pll_14nm_vco_prepare] *ERROR* DSI PLL lock failed ------------[ cut here ]------------ dsi0pllbyte already disabled WARNING: CPU: 3 PID: 1 at drivers/clk/clk.c:1194 clk_core_disable+0xa4/0xac CPU: 3 UID: 0 PID: 1 Comm: swapper/0 Tainted: Tainted: [W]=WARN Hardware name: Qualcomm Technologies, Inc. Robotics RB1 (DT) pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [...] ``` This issue is particularly prevalent at boot time during the disabling of unused clocks (clk_disable_unused()) which includes enabling the parent clock(s) when CLK_OPS_PARENT_ENABLE flag is set (this is the case for the 14nm DSI PHY PLL consumers). To resolve this issue, we move the AHB clock as a PM dependency of the DSI PHY device (via pm_clk). Since the DSI PHY device is the parent of the PLL clocks, this resolves the PLL/AHB dependency. Now the AHB clock is enabled prior the PLL clk_prepare callback, as part of the runtime-resume chain. We also eliminate dsi_phy_[enable|disable]_resource functions, which are superseded by runtime PM. Note that it breaks compatibility with kernels before 6.0, as we do not support anymore the legacy `iface_clk` name. Signed-off-by: Loic Poulain Reviewed-by: Dmitry Baryshkov Patchwork: https://patchwork.freedesktop.org/patch/663239/ Link: https://lore.kernel.org/r/20250709140836.124143-1-loic.poulain@oss.qualcomm.com Signed-off-by: Dmitry Baryshkov --- diff --git a/drivers/gpu/drm/msm/dsi/phy/dsi_phy.c b/drivers/gpu/drm/msm/dsi/phy/dsi_phy.c index 221f12db5f8b7..4ea681130dbaf 100644 --- a/drivers/gpu/drm/msm/dsi/phy/dsi_phy.c +++ b/drivers/gpu/drm/msm/dsi/phy/dsi_phy.c @@ -5,6 +5,8 @@ #include #include +#include +#include #include #include "dsi_phy.h" @@ -511,30 +513,6 @@ int msm_dsi_cphy_timing_calc_v4(struct msm_dsi_dphy_timing *timing, return 0; } -static int dsi_phy_enable_resource(struct msm_dsi_phy *phy) -{ - struct device *dev = &phy->pdev->dev; - int ret; - - ret = pm_runtime_resume_and_get(dev); - if (ret) - return ret; - - ret = clk_prepare_enable(phy->ahb_clk); - if (ret) { - DRM_DEV_ERROR(dev, "%s: can't enable ahb clk, %d\n", __func__, ret); - pm_runtime_put_sync(dev); - } - - return ret; -} - -static void dsi_phy_disable_resource(struct msm_dsi_phy *phy) -{ - clk_disable_unprepare(phy->ahb_clk); - pm_runtime_put(&phy->pdev->dev); -} - static const struct of_device_id dsi_phy_dt_match[] = { #ifdef CONFIG_DRM_MSM_DSI_28NM_PHY { .compatible = "qcom,dsi-phy-28nm-hpm", @@ -698,22 +676,20 @@ static int dsi_phy_driver_probe(struct platform_device *pdev) if (ret) return ret; - phy->ahb_clk = msm_clk_get(pdev, "iface"); - if (IS_ERR(phy->ahb_clk)) - return dev_err_probe(dev, PTR_ERR(phy->ahb_clk), - "Unable to get ahb clk\n"); + platform_set_drvdata(pdev, phy); - ret = devm_pm_runtime_enable(&pdev->dev); + ret = devm_pm_runtime_enable(dev); if (ret) return ret; - /* PLL init will call into clk_register which requires - * register access, so we need to enable power and ahb clock. - */ - ret = dsi_phy_enable_resource(phy); + ret = devm_pm_clk_create(dev); if (ret) return ret; + ret = pm_clk_add(dev, "iface"); + if (ret < 0) + return dev_err_probe(dev, ret, "Unable to get iface clk\n"); + if (phy->cfg->ops.pll_init) { ret = phy->cfg->ops.pll_init(phy); if (ret) @@ -727,18 +703,19 @@ static int dsi_phy_driver_probe(struct platform_device *pdev) return dev_err_probe(dev, ret, "Failed to register clk provider\n"); - dsi_phy_disable_resource(phy); - - platform_set_drvdata(pdev, phy); - return 0; } +static const struct dev_pm_ops dsi_phy_pm_ops = { + SET_RUNTIME_PM_OPS(pm_clk_suspend, pm_clk_resume, NULL) +}; + static struct platform_driver dsi_phy_platform_driver = { .probe = dsi_phy_driver_probe, .driver = { .name = "msm_dsi_phy", .of_match_table = dsi_phy_dt_match, + .pm = &dsi_phy_pm_ops, }, }; @@ -764,9 +741,9 @@ int msm_dsi_phy_enable(struct msm_dsi_phy *phy, dev = &phy->pdev->dev; - ret = dsi_phy_enable_resource(phy); + ret = pm_runtime_resume_and_get(dev); if (ret) { - DRM_DEV_ERROR(dev, "%s: resource enable failed, %d\n", + DRM_DEV_ERROR(dev, "%s: resume failed, %d\n", __func__, ret); goto res_en_fail; } @@ -810,7 +787,7 @@ pll_restor_fail: phy_en_fail: regulator_bulk_disable(phy->cfg->num_regulators, phy->supplies); reg_en_fail: - dsi_phy_disable_resource(phy); + pm_runtime_put(dev); res_en_fail: return ret; } @@ -823,7 +800,7 @@ void msm_dsi_phy_disable(struct msm_dsi_phy *phy) phy->cfg->ops.disable(phy); regulator_bulk_disable(phy->cfg->num_regulators, phy->supplies); - dsi_phy_disable_resource(phy); + pm_runtime_put(&phy->pdev->dev); } void msm_dsi_phy_set_usecase(struct msm_dsi_phy *phy, diff --git a/drivers/gpu/drm/msm/dsi/phy/dsi_phy.h b/drivers/gpu/drm/msm/dsi/phy/dsi_phy.h index c558f8df16847..3cbf082314924 100644 --- a/drivers/gpu/drm/msm/dsi/phy/dsi_phy.h +++ b/drivers/gpu/drm/msm/dsi/phy/dsi_phy.h @@ -104,7 +104,6 @@ struct msm_dsi_phy { phys_addr_t lane_size; int id; - struct clk *ahb_clk; struct regulator_bulk_data *supplies; struct msm_dsi_dphy_timing timing;