6.17-stable review patch. If anyone has any objections, please let me know.
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From: Leo Yan leo.yan@arm.com
[ Upstream commit d091c6312561821f216ced63a7ad17c946b6d335 ]
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... Signed-off-by: Sasha Levin sashal@kernel.org --- include/linux/coresight.h | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-)
diff --git a/include/linux/coresight.h b/include/linux/coresight.h index 1e652e1578419..bb49080ec8f96 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; }