diff options
| author | Leo Yan <leo.yan@arm.com> | 2025-07-31 13:23:42 +0100 |
|---|---|---|
| committer | Suzuki K Poulose <suzuki.poulose@arm.com> | 2025-09-23 14:14:12 +0100 |
| commit | d091c6312561821f216ced63a7ad17c946b6d335 (patch) | |
| tree | 9b4f7a459ebc7038e8ef4d3ad77296aca2fdb415 | |
| parent | a8f2d480f19d912f15dbac7038cd578d6b8b4d74 (diff) | |
coresight: Avoid enable programming clock duplicately
The programming clock is enabled by AMBA bus driver before a dynamic
probe. As a result, a CoreSight driver may redundantly enable the same
clock.
To avoid this, add a check for device type and skip enabling the
programming clock for AMBA devices. The returned NULL pointer will be
tolerated by the drivers.
Fixes: 73d779a03a76 ("coresight: etm4x: Change etm4_platform_driver driver for MMIO devices")
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Yeoreum Yun <yeoreum.yun@arm.com>
Tested-by: James Clark <james.clark@linaro.org>
Signed-off-by: Leo Yan <leo.yan@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20250731-arm_cs_fix_clock_v4-v6-6-1dfe10bb3f6f@arm.com
| -rw-r--r-- | include/linux/coresight.h | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/include/linux/coresight.h b/include/linux/coresight.h index 1e652e157841..bb49080ec8f9 100644 --- a/include/linux/coresight.h +++ b/include/linux/coresight.h @@ -481,20 +481,23 @@ static inline bool is_coresight_device(void __iomem *base) * Returns: * * clk - Clock is found and enabled - * NULL - Clock is controlled by firmware (ACPI device only) + * NULL - Clock is controlled by firmware (ACPI device only) or when managed + * by the AMBA bus driver instead * ERROR - Clock is found but failed to enable */ static inline struct clk *coresight_get_enable_apb_pclk(struct device *dev) { - struct clk *pclk; + struct clk *pclk = NULL; /* Firmware controls clocks for an ACPI device. */ if (has_acpi_companion(dev)) return NULL; - pclk = devm_clk_get_optional_enabled(dev, "apb_pclk"); - if (!pclk) - pclk = devm_clk_get_optional_enabled(dev, "apb"); + if (!dev_is_amba(dev)) { + pclk = devm_clk_get_optional_enabled(dev, "apb_pclk"); + if (!pclk) + pclk = devm_clk_get_optional_enabled(dev, "apb"); + } return pclk; } |