From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops There's some internal state that ftrace_ops needs to have set, but since it can be declared outside of the ftrace.c code, it calls ftrace_ops_init() on the ops in every global function. The issue is that if two tasks call it on the same ops at the same time it is possible to have the initialization of one corrupt the initialization of the other call. Create a ops_mutex to use to synchronize every initialization of the ftrace_ops. The mutex is taken within checking the ftrace_ops flag that states it was initializied but the flag is checked again after the mutex has been taken. Checking first outside the mutex allows it to shortcut having to take the mutex. But then the check needs to be done again after the mute is taken in case of races. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock") Reported-by: sashiko-bot@kernel.org Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/ Signed-off-by: Steven Rostedt --- drivers/phy/mediatek/phy-mtk-dp.c | 202 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 202 insertions(+) create mode 100644 drivers/phy/mediatek/phy-mtk-dp.c (limited to 'drivers/phy/mediatek/phy-mtk-dp.c') diff --git a/drivers/phy/mediatek/phy-mtk-dp.c b/drivers/phy/mediatek/phy-mtk-dp.c new file mode 100644 index 000000000..d7024a144 --- /dev/null +++ b/drivers/phy/mediatek/phy-mtk-dp.c @@ -0,0 +1,202 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * MediaTek DisplayPort PHY driver + * + * Copyright (c) 2022, BayLibre Inc. + * Copyright (c) 2022, MediaTek Inc. + */ + +#include +#include +#include +#include +#include +#include +#include + +#define PHY_OFFSET 0x1000 + +#define MTK_DP_PHY_DIG_PLL_CTL_1 (PHY_OFFSET + 0x14) +#define TPLL_SSC_EN BIT(3) + +#define MTK_DP_PHY_DIG_BIT_RATE (PHY_OFFSET + 0x3C) +#define BIT_RATE_RBR 0 +#define BIT_RATE_HBR 1 +#define BIT_RATE_HBR2 2 +#define BIT_RATE_HBR3 3 + +#define MTK_DP_PHY_DIG_SW_RST (PHY_OFFSET + 0x38) +#define DP_GLB_SW_RST_PHYD BIT(0) + +#define MTK_DP_LANE0_DRIVING_PARAM_3 (PHY_OFFSET + 0x138) +#define MTK_DP_LANE1_DRIVING_PARAM_3 (PHY_OFFSET + 0x238) +#define MTK_DP_LANE2_DRIVING_PARAM_3 (PHY_OFFSET + 0x338) +#define MTK_DP_LANE3_DRIVING_PARAM_3 (PHY_OFFSET + 0x438) +#define XTP_LN_TX_LCTXC0_SW0_PRE0_DEFAULT BIT(4) +#define XTP_LN_TX_LCTXC0_SW0_PRE1_DEFAULT (BIT(10) | BIT(12)) +#define XTP_LN_TX_LCTXC0_SW0_PRE2_DEFAULT GENMASK(20, 19) +#define XTP_LN_TX_LCTXC0_SW0_PRE3_DEFAULT GENMASK(29, 29) +#define DRIVING_PARAM_3_DEFAULT (XTP_LN_TX_LCTXC0_SW0_PRE0_DEFAULT | \ + XTP_LN_TX_LCTXC0_SW0_PRE1_DEFAULT | \ + XTP_LN_TX_LCTXC0_SW0_PRE2_DEFAULT | \ + XTP_LN_TX_LCTXC0_SW0_PRE3_DEFAULT) + +#define XTP_LN_TX_LCTXC0_SW1_PRE0_DEFAULT GENMASK(4, 3) +#define XTP_LN_TX_LCTXC0_SW1_PRE1_DEFAULT GENMASK(12, 9) +#define XTP_LN_TX_LCTXC0_SW1_PRE2_DEFAULT (BIT(18) | BIT(21)) +#define XTP_LN_TX_LCTXC0_SW2_PRE0_DEFAULT GENMASK(29, 29) +#define DRIVING_PARAM_4_DEFAULT (XTP_LN_TX_LCTXC0_SW1_PRE0_DEFAULT | \ + XTP_LN_TX_LCTXC0_SW1_PRE1_DEFAULT | \ + XTP_LN_TX_LCTXC0_SW1_PRE2_DEFAULT | \ + XTP_LN_TX_LCTXC0_SW2_PRE0_DEFAULT) + +#define XTP_LN_TX_LCTXC0_SW2_PRE1_DEFAULT (BIT(3) | BIT(5)) +#define XTP_LN_TX_LCTXC0_SW3_PRE0_DEFAULT GENMASK(13, 12) +#define DRIVING_PARAM_5_DEFAULT (XTP_LN_TX_LCTXC0_SW2_PRE1_DEFAULT | \ + XTP_LN_TX_LCTXC0_SW3_PRE0_DEFAULT) + +#define XTP_LN_TX_LCTXCP1_SW0_PRE0_DEFAULT 0 +#define XTP_LN_TX_LCTXCP1_SW0_PRE1_DEFAULT GENMASK(10, 10) +#define XTP_LN_TX_LCTXCP1_SW0_PRE2_DEFAULT GENMASK(19, 19) +#define XTP_LN_TX_LCTXCP1_SW0_PRE3_DEFAULT GENMASK(28, 28) +#define DRIVING_PARAM_6_DEFAULT (XTP_LN_TX_LCTXCP1_SW0_PRE0_DEFAULT | \ + XTP_LN_TX_LCTXCP1_SW0_PRE1_DEFAULT | \ + XTP_LN_TX_LCTXCP1_SW0_PRE2_DEFAULT | \ + XTP_LN_TX_LCTXCP1_SW0_PRE3_DEFAULT) + +#define XTP_LN_TX_LCTXCP1_SW1_PRE0_DEFAULT 0 +#define XTP_LN_TX_LCTXCP1_SW1_PRE1_DEFAULT GENMASK(10, 9) +#define XTP_LN_TX_LCTXCP1_SW1_PRE2_DEFAULT GENMASK(19, 18) +#define XTP_LN_TX_LCTXCP1_SW2_PRE0_DEFAULT 0 +#define DRIVING_PARAM_7_DEFAULT (XTP_LN_TX_LCTXCP1_SW1_PRE0_DEFAULT | \ + XTP_LN_TX_LCTXCP1_SW1_PRE1_DEFAULT | \ + XTP_LN_TX_LCTXCP1_SW1_PRE2_DEFAULT | \ + XTP_LN_TX_LCTXCP1_SW2_PRE0_DEFAULT) + +#define XTP_LN_TX_LCTXCP1_SW2_PRE1_DEFAULT GENMASK(3, 3) +#define XTP_LN_TX_LCTXCP1_SW3_PRE0_DEFAULT 0 +#define DRIVING_PARAM_8_DEFAULT (XTP_LN_TX_LCTXCP1_SW2_PRE1_DEFAULT | \ + XTP_LN_TX_LCTXCP1_SW3_PRE0_DEFAULT) + +struct mtk_dp_phy { + struct regmap *regs; +}; + +static int mtk_dp_phy_init(struct phy *phy) +{ + struct mtk_dp_phy *dp_phy = phy_get_drvdata(phy); + static const u32 driving_params[] = { + DRIVING_PARAM_3_DEFAULT, + DRIVING_PARAM_4_DEFAULT, + DRIVING_PARAM_5_DEFAULT, + DRIVING_PARAM_6_DEFAULT, + DRIVING_PARAM_7_DEFAULT, + DRIVING_PARAM_8_DEFAULT + }; + + regmap_bulk_write(dp_phy->regs, MTK_DP_LANE0_DRIVING_PARAM_3, + driving_params, ARRAY_SIZE(driving_params)); + regmap_bulk_write(dp_phy->regs, MTK_DP_LANE1_DRIVING_PARAM_3, + driving_params, ARRAY_SIZE(driving_params)); + regmap_bulk_write(dp_phy->regs, MTK_DP_LANE2_DRIVING_PARAM_3, + driving_params, ARRAY_SIZE(driving_params)); + regmap_bulk_write(dp_phy->regs, MTK_DP_LANE3_DRIVING_PARAM_3, + driving_params, ARRAY_SIZE(driving_params)); + + return 0; +} + +static int mtk_dp_phy_configure(struct phy *phy, union phy_configure_opts *opts) +{ + struct mtk_dp_phy *dp_phy = phy_get_drvdata(phy); + u32 val; + + if (opts->dp.set_rate) { + switch (opts->dp.link_rate) { + default: + dev_err(&phy->dev, + "Implementation error, unknown linkrate %x\n", + opts->dp.link_rate); + return -EINVAL; + case 1620: + val = BIT_RATE_RBR; + break; + case 2700: + val = BIT_RATE_HBR; + break; + case 5400: + val = BIT_RATE_HBR2; + break; + case 8100: + val = BIT_RATE_HBR3; + break; + } + regmap_write(dp_phy->regs, MTK_DP_PHY_DIG_BIT_RATE, val); + } + + regmap_update_bits(dp_phy->regs, MTK_DP_PHY_DIG_PLL_CTL_1, + TPLL_SSC_EN, opts->dp.ssc ? TPLL_SSC_EN : 0); + + return 0; +} + +static int mtk_dp_phy_reset(struct phy *phy) +{ + struct mtk_dp_phy *dp_phy = phy_get_drvdata(phy); + + regmap_update_bits(dp_phy->regs, MTK_DP_PHY_DIG_SW_RST, + DP_GLB_SW_RST_PHYD, 0); + usleep_range(50, 200); + regmap_update_bits(dp_phy->regs, MTK_DP_PHY_DIG_SW_RST, + DP_GLB_SW_RST_PHYD, 1); + + return 0; +} + +static const struct phy_ops mtk_dp_phy_dev_ops = { + .init = mtk_dp_phy_init, + .configure = mtk_dp_phy_configure, + .reset = mtk_dp_phy_reset, + .owner = THIS_MODULE, +}; + +static int mtk_dp_phy_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct mtk_dp_phy *dp_phy; + struct phy *phy; + struct regmap *regs; + + regs = *(struct regmap **)dev->platform_data; + if (!regs) + return dev_err_probe(dev, -EINVAL, + "No data passed, requires struct regmap**\n"); + + dp_phy = devm_kzalloc(dev, sizeof(*dp_phy), GFP_KERNEL); + if (!dp_phy) + return -ENOMEM; + + dp_phy->regs = regs; + phy = devm_phy_create(dev, NULL, &mtk_dp_phy_dev_ops); + if (IS_ERR(phy)) + return dev_err_probe(dev, PTR_ERR(phy), + "Failed to create DP PHY\n"); + + phy_set_drvdata(phy, dp_phy); + if (!dev->of_node) + phy_create_lookup(phy, "dp", dev_name(dev)); + + return 0; +} + +static struct platform_driver mtk_dp_phy_driver = { + .probe = mtk_dp_phy_probe, + .driver = { + .name = "mediatek-dp-phy", + }, +}; +module_platform_driver(mtk_dp_phy_driver); + +MODULE_AUTHOR("Markus Schneider-Pargmann "); +MODULE_DESCRIPTION("MediaTek DP PHY Driver"); +MODULE_LICENSE("GPL"); -- cgit v1.3.1