This is a note to let you know that I've just added the patch titled regulator: core: fix deadlock on regulator enable to the 6.0-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: regulator-core-fix-deadlock-on-regulator-enable.patch and it can be found in the queue-6.0 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From cb3543cff90a4448ed560ac86c98033ad5fecda9 Mon Sep 17 00:00:00 2001 From: Johan Hovold <johan+linaro@xxxxxxxxxx> Date: Thu, 15 Dec 2022 11:46:46 +0100 Subject: regulator: core: fix deadlock on regulator enable From: Johan Hovold <johan+linaro@xxxxxxxxxx> commit cb3543cff90a4448ed560ac86c98033ad5fecda9 upstream. When updating the operating mode as part of regulator enable, the caller has already locked the regulator tree and drms_uA_update() must not try to do the same in order not to trigger a deadlock. The lock inversion is reported by lockdep as: ====================================================== WARNING: possible circular locking dependency detected 6.1.0-next-20221215 #142 Not tainted ------------------------------------------------------ udevd/154 is trying to acquire lock: ffffc11f123d7e50 (regulator_list_mutex){+.+.}-{3:3}, at: regulator_lock_dependent+0x54/0x280 but task is already holding lock: ffff80000e4c36e8 (regulator_ww_class_acquire){+.+.}-{0:0}, at: regulator_enable+0x34/0x80 which lock already depends on the new lock. ... Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(regulator_ww_class_acquire); lock(regulator_list_mutex); lock(regulator_ww_class_acquire); lock(regulator_list_mutex); *** DEADLOCK *** just before probe of a Qualcomm UFS controller (occasionally) deadlocks when enabling one of its regulators. Fixes: 9243a195be7a ("regulator: core: Change voltage setting path") Fixes: f8702f9e4aa7 ("regulator: core: Use ww_mutex for regulators locking") Cc: stable@xxxxxxxxxxxxxxx # 5.0 Signed-off-by: Johan Hovold <johan+linaro@xxxxxxxxxx> Link: https://lore.kernel.org/r/20221215104646.19818-1-johan+linaro@xxxxxxxxxx Signed-off-by: Mark Brown <broonie@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/regulator/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -987,7 +987,7 @@ static int drms_uA_update(struct regulat /* get input voltage */ input_uV = 0; if (rdev->supply) - input_uV = regulator_get_voltage(rdev->supply); + input_uV = regulator_get_voltage_rdev(rdev->supply->rdev); if (input_uV <= 0) input_uV = rdev->constraints->input_uV; if (input_uV <= 0) { Patches currently in stable-queue which might be from johan+linaro@xxxxxxxxxx are queue-6.0/arm64-dts-qcom-sm8450-fix-ufs-phy-registers.patch queue-6.0/arm64-dts-qcom-sm8250-fix-ufs-phy-registers.patch queue-6.0/arm64-dts-qcom-sm8250-drop-bogus-dp-phy-clock.patch queue-6.0/arm64-dts-qcom-sm6350-fix-usb-dp-phy-registers.patch queue-6.0/arm64-dts-qcom-sm8250-fix-usb-dp-phy-registers.patch queue-6.0/arm64-dts-qcom-sm8350-fix-ufs-phy-registers.patch queue-6.0/arm64-dts-qcom-sm6350-drop-bogus-dp-phy-clock.patch queue-6.0/arm64-dts-qcom-sm8150-fix-ufs-phy-registers.patch queue-6.0/phy-qcom-qmp-pcie-fix-ipq8074-gen3-initialisation.patch queue-6.0/phy-qcom-qmp-pcie-drop-bogus-register-update.patch queue-6.0/regulator-core-fix-deadlock-on-regulator-enable.patch