We must free/disable all interrupts and cancel all pending works before doing further cleanup.
Before this commit arizona_extcon_remove() was doing several register writes to shut things down before disabling the IRQs and it was cancelling only 1 of the 3 different works used.
Move all the register-writes shutting things down to after the disabling of the IRQs and add the 2 missing cancel_delayed_work_sync() calls.
This fixes various possible races on driver unbind. One of which would always trigger on devices using the mic-clamp feature for jack detection. The ARIZONA_MICD_CLAMP_MODE_MASK update was done before disabling the IRQs, causing: 1. arizona_jackdet() to run 2. detect a jack being inserted (clamp disabled means jack inserted) 3. call arizona_start_mic() which: 3.1 Enables the MICVDD regulator 3.2 takes a pm_runtime_reference
And this was all happening after the ARIZONA_MICD_ENA bit clearing, which would undo 3.1 and 3.2 because the ARIZONA_MICD_CLAMP_MODE_MASK update was being done after the ARIZONA_MICD_ENA bit clearing.
So this means that arizona_extcon_remove() would exit with 1. MICVDD enabled and 2. The pm_runtime_reference being unbalanced.
MICVDD still being enabled caused the following oops when the regulator is released by the devm framework:
[ 2850.745757] ------------[ cut here ]------------ [ 2850.745827] WARNING: CPU: 2 PID: 2098 at drivers/regulator/core.c:2123 _regulator_put.part.0+0x19f/0x1b0 [ 2850.745835] Modules linked in: extcon_arizona ... ... [ 2850.746909] Call Trace: [ 2850.746932] regulator_put+0x2d/0x40 [ 2850.746946] release_nodes+0x22a/0x260 [ 2850.746984] __device_release_driver+0x190/0x240 [ 2850.747002] driver_detach+0xd4/0x120 ... [ 2850.747337] ---[ end trace f455dfd7abd9781f ]---
Note this oops is just one of various theoretically possible races caused by the wrong ordering inside arizona_extcon_remove(), this fixes the ordering fixing all possible races, including the reported oops.
Reviewed-by: Andy Shevchenko andy.shevchenko@gmail.com Acked-by: Charles Keepax ckeepax@opensource.cirrus.com Tested-by: Charles Keepax ckeepax@opensource.cirrus.com Signed-off-by: Hans de Goede hdegoede@redhat.com --- drivers/extcon/extcon-arizona.c | 40 +++++++++++++++++---------------- 1 file changed, 21 insertions(+), 19 deletions(-)
diff --git a/drivers/extcon/extcon-arizona.c b/drivers/extcon/extcon-arizona.c index f7ef247de46a..76aacbac5869 100644 --- a/drivers/extcon/extcon-arizona.c +++ b/drivers/extcon/extcon-arizona.c @@ -1760,25 +1760,6 @@ static int arizona_extcon_remove(struct platform_device *pdev) bool change; int ret;
- ret = regmap_update_bits_check(arizona->regmap, ARIZONA_MIC_DETECT_1, - ARIZONA_MICD_ENA, 0, - &change); - if (ret < 0) { - dev_err(&pdev->dev, "Failed to disable micd on remove: %d\n", - ret); - } else if (change) { - regulator_disable(info->micvdd); - pm_runtime_put(info->dev); - } - - gpiod_put(info->micd_pol_gpio); - - pm_runtime_disable(&pdev->dev); - - regmap_update_bits(arizona->regmap, - ARIZONA_MICD_CLAMP_CONTROL, - ARIZONA_MICD_CLAMP_MODE_MASK, 0); - if (info->micd_clamp) { jack_irq_rise = ARIZONA_IRQ_MICD_CLAMP_RISE; jack_irq_fall = ARIZONA_IRQ_MICD_CLAMP_FALL; @@ -1794,10 +1775,31 @@ static int arizona_extcon_remove(struct platform_device *pdev) arizona_free_irq(arizona, jack_irq_rise, info); arizona_free_irq(arizona, jack_irq_fall, info); cancel_delayed_work_sync(&info->hpdet_work); + cancel_delayed_work_sync(&info->micd_detect_work); + cancel_delayed_work_sync(&info->micd_timeout_work); + + ret = regmap_update_bits_check(arizona->regmap, ARIZONA_MIC_DETECT_1, + ARIZONA_MICD_ENA, 0, + &change); + if (ret < 0) { + dev_err(&pdev->dev, "Failed to disable micd on remove: %d\n", + ret); + } else if (change) { + regulator_disable(info->micvdd); + pm_runtime_put(info->dev); + } + + regmap_update_bits(arizona->regmap, + ARIZONA_MICD_CLAMP_CONTROL, + ARIZONA_MICD_CLAMP_MODE_MASK, 0); regmap_update_bits(arizona->regmap, ARIZONA_JACK_DETECT_ANALOGUE, ARIZONA_JD1_ENA, 0); arizona_clk32k_disable(arizona);
+ gpiod_put(info->micd_pol_gpio); + + pm_runtime_disable(&pdev->dev); + return 0; }