From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: "Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
stable@vger.kernel.org, "Sascha Hauer" <s.hauer@pengutronix.de>,
"Shawn Guo" <shawnguo@kernel.org>,
"Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>,
"Thierry Reding" <thierry.reding@gmail.com>
Subject: [PATCH 5.4 26/50] pwm: mxs: Dont modify HW state in .probe() after the PWM chip was registered
Date: Fri, 24 Sep 2021 14:44:15 +0200 [thread overview]
Message-ID: <20210924124333.128621963@linuxfoundation.org> (raw)
In-Reply-To: <20210924124332.229289734@linuxfoundation.org>
From: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
commit 020162d6f49f2963062229814a56a89c86cbeaa8 upstream.
This fixes a race condition: After pwmchip_add() is called there might
already be a consumer and then modifying the hardware behind the
consumer's back is bad. So reset before calling pwmchip_add().
Note that reseting the hardware isn't the right thing to do if the PWM
is already running as it might e.g. disable (or even enable) a backlight
that is supposed to be on (or off).
Fixes: 4dce82c1e840 ("pwm: add pwm-mxs support")
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/pwm/pwm-mxs.c | 13 +++++--------
1 file changed, 5 insertions(+), 8 deletions(-)
--- a/drivers/pwm/pwm-mxs.c
+++ b/drivers/pwm/pwm-mxs.c
@@ -150,6 +150,11 @@ static int mxs_pwm_probe(struct platform
return ret;
}
+ /* FIXME: Only do this if the PWM isn't already running */
+ ret = stmp_reset_block(mxs->base);
+ if (ret)
+ return dev_err_probe(&pdev->dev, ret, "failed to reset PWM\n");
+
ret = pwmchip_add(&mxs->chip);
if (ret < 0) {
dev_err(&pdev->dev, "failed to add pwm chip %d\n", ret);
@@ -158,15 +163,7 @@ static int mxs_pwm_probe(struct platform
platform_set_drvdata(pdev, mxs);
- ret = stmp_reset_block(mxs->base);
- if (ret)
- goto pwm_remove;
-
return 0;
-
-pwm_remove:
- pwmchip_remove(&mxs->chip);
- return ret;
}
static int mxs_pwm_remove(struct platform_device *pdev)
next prev parent reply other threads:[~2021-09-24 12:54 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-24 12:43 [PATCH 5.4 00/50] 5.4.149-rc1 review Greg Kroah-Hartman
2021-09-24 12:43 ` [PATCH 5.4 01/50] PCI: pci-bridge-emul: Fix big-endian support Greg Kroah-Hartman
2021-09-24 12:43 ` [PATCH 5.4 02/50] PCI: aardvark: Indicate error in val when config read fails Greg Kroah-Hartman
2021-09-24 12:43 ` [PATCH 5.4 03/50] PCI: pci-bridge-emul: Add PCIe Root Capabilities Register Greg Kroah-Hartman
2021-09-24 12:43 ` [PATCH 5.4 04/50] PCI: aardvark: Fix reporting CRS value Greg Kroah-Hartman
2021-09-24 12:43 ` [PATCH 5.4 05/50] PCI/ACPI: Add Ampere Altra SOC MCFG quirk Greg Kroah-Hartman
2021-09-24 12:43 ` [PATCH 5.4 06/50] KVM: remember position in kvm->vcpus array Greg Kroah-Hartman
2021-09-24 12:43 ` [PATCH 5.4 07/50] console: consume APC, DM, DCS Greg Kroah-Hartman
2021-09-24 12:43 ` [PATCH 5.4 08/50] s390/pci_mmio: fully validate the VMA before calling follow_pte() Greg Kroah-Hartman
2021-09-24 12:43 ` [PATCH 5.4 09/50] ARM: Qualify enabling of swiotlb_init() Greg Kroah-Hartman
2021-09-24 12:43 ` [PATCH 5.4 10/50] apparmor: remove duplicate macro list_entry_is_head() Greg Kroah-Hartman
2021-09-24 12:44 ` [PATCH 5.4 11/50] ARM: 9077/1: PLT: Move struct plt_entries definition to header Greg Kroah-Hartman
2021-09-24 12:44 ` [PATCH 5.4 12/50] ARM: 9078/1: Add warn suppress parameter to arm_gen_branch_link() Greg Kroah-Hartman
2021-09-24 12:44 ` [PATCH 5.4 13/50] ARM: 9079/1: ftrace: Add MODULE_PLTS support Greg Kroah-Hartman
2021-09-24 12:44 ` [PATCH 5.4 14/50] ARM: 9098/1: ftrace: MODULE_PLT: Fix build problem without DYNAMIC_FTRACE Greg Kroah-Hartman
2021-09-24 12:44 ` [PATCH 5.4 15/50] sctp: validate chunk size in __rcv_asconf_lookup Greg Kroah-Hartman
2021-09-24 12:44 ` [PATCH 5.4 16/50] sctp: add param size validation for SCTP_PARAM_SET_PRIMARY Greg Kroah-Hartman
2021-09-24 12:44 ` [PATCH 5.4 17/50] staging: rtl8192u: Fix bitwise vs logical operator in TranslateRxSignalStuff819xUsb() Greg Kroah-Hartman
2021-09-24 12:44 ` [PATCH 5.4 18/50] um: virtio_uml: fix memory leak on init failures Greg Kroah-Hartman
2021-09-24 12:44 ` [PATCH 5.4 19/50] dmaengine: acpi: Avoid comparison GSI with Linux vIRQ Greg Kroah-Hartman
2021-09-24 12:44 ` [PATCH 5.4 20/50] thermal/drivers/exynos: Fix an error code in exynos_tmu_probe() Greg Kroah-Hartman
2021-09-24 12:44 ` [PATCH 5.4 21/50] 9p/trans_virtio: Remove sysfs file on probe failure Greg Kroah-Hartman
2021-09-24 12:44 ` [PATCH 5.4 22/50] prctl: allow to setup brk for et_dyn executables Greg Kroah-Hartman
2021-09-24 12:44 ` [PATCH 5.4 23/50] nilfs2: use refcount_dec_and_lock() to fix potential UAF Greg Kroah-Hartman
2021-09-24 12:44 ` [PATCH 5.4 24/50] profiling: fix shift-out-of-bounds bugs Greg Kroah-Hartman
2021-09-24 12:44 ` [PATCH 5.4 25/50] pwm: lpc32xx: Dont modify HW state in .probe() after the PWM chip was registered Greg Kroah-Hartman
2021-09-24 12:44 ` Greg Kroah-Hartman [this message]
2021-09-24 12:44 ` [PATCH 5.4 27/50] phy: avoid unnecessary link-up delay in polling mode Greg Kroah-Hartman
2021-09-24 12:44 ` [PATCH 5.4 28/50] net: stmmac: reset Tx desc base address before restarting Tx Greg Kroah-Hartman
2021-09-24 12:44 ` [PATCH 5.4 29/50] Kconfig.debug: drop selecting non-existing HARDLOCKUP_DETECTOR_ARCH Greg Kroah-Hartman
2021-09-24 12:44 ` [PATCH 5.4 30/50] thermal/core: Fix thermal_cooling_device_register() prototype Greg Kroah-Hartman
2021-09-24 12:44 ` [PATCH 5.4 31/50] drivers: base: cacheinfo: Get rid of DEFINE_SMP_CALL_CACHE_FUNCTION() Greg Kroah-Hartman
2021-09-24 12:44 ` [PATCH 5.4 32/50] parisc: Move pci_dev_is_behind_card_dino to where it is used Greg Kroah-Hartman
2021-09-24 12:44 ` [PATCH 5.4 33/50] dmaengine: sprd: Add missing MODULE_DEVICE_TABLE Greg Kroah-Hartman
2021-09-24 12:44 ` [PATCH 5.4 34/50] dmaengine: ioat: depends on !UML Greg Kroah-Hartman
2021-09-24 12:44 ` [PATCH 5.4 35/50] dmaengine: xilinx_dma: Set DMA mask for coherent APIs Greg Kroah-Hartman
2021-09-24 12:44 ` [PATCH 5.4 36/50] ceph: request Fw caps before updating the mtime in ceph_write_iter Greg Kroah-Hartman
2021-09-24 12:44 ` [PATCH 5.4 37/50] ceph: lockdep annotations for try_nonblocking_invalidate Greg Kroah-Hartman
2021-09-24 12:44 ` [PATCH 5.4 38/50] btrfs: fix lockdep warning while mounting sprout fs Greg Kroah-Hartman
2021-09-24 12:44 ` [PATCH 5.4 39/50] nilfs2: fix memory leak in nilfs_sysfs_create_device_group Greg Kroah-Hartman
2021-09-24 12:44 ` [PATCH 5.4 40/50] nilfs2: fix NULL pointer in nilfs_##name##_attr_release Greg Kroah-Hartman
2021-09-24 12:44 ` [PATCH 5.4 41/50] nilfs2: fix memory leak in nilfs_sysfs_create_##name##_group Greg Kroah-Hartman
2021-09-24 12:44 ` [PATCH 5.4 42/50] nilfs2: fix memory leak in nilfs_sysfs_delete_##name##_group Greg Kroah-Hartman
2021-09-24 12:44 ` [PATCH 5.4 43/50] nilfs2: fix memory leak in nilfs_sysfs_create_snapshot_group Greg Kroah-Hartman
2021-09-24 12:44 ` [PATCH 5.4 44/50] nilfs2: fix memory leak in nilfs_sysfs_delete_snapshot_group Greg Kroah-Hartman
2021-09-24 12:44 ` [PATCH 5.4 45/50] pwm: img: Dont modify HW state in .remove() callback Greg Kroah-Hartman
2021-09-24 12:44 ` [PATCH 5.4 46/50] pwm: rockchip: " Greg Kroah-Hartman
2021-09-24 12:44 ` [PATCH 5.4 47/50] pwm: stm32-lp: " Greg Kroah-Hartman
2021-09-24 12:44 ` [PATCH 5.4 48/50] blk-throttle: fix UAF by deleteing timer in blk_throtl_exit() Greg Kroah-Hartman
2021-09-24 12:44 ` [PATCH 5.4 49/50] rtc: rx8010: select REGMAP_I2C Greg Kroah-Hartman
2021-09-24 12:44 ` [PATCH 5.4 50/50] drm/nouveau/nvkm: Replace -ENOSYS with -ENODEV Greg Kroah-Hartman
2021-09-24 14:03 ` [PATCH 5.4 00/50] 5.4.149-rc1 review Daniel Díaz
2021-09-24 17:59 ` Jon Hunter
2021-09-24 21:53 ` Shuah Khan
2021-09-24 22:03 ` Florian Fainelli
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