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authorHans de Goede <hdegoede@redhat.com>2021-03-07 16:17:57 +0100
committerLee Jones <lee.jones@linaro.org>2021-03-18 11:46:15 +0000
commite5b499f6fb17bc95a813e85d0796522280203806 (patch)
treea4fb5c7b9617b5d0e4ebfdf20779e61b985dfc62 /drivers/extcon
parentc309a3e8793f7e01c4a4ec7960658380572cb576 (diff)
extcon: arizona: Fix various races on driver unbind
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. Signed-off-by: Hans de Goede <hdegoede@redhat.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Acked-by: Charles Keepax <ckeepax@opensource.cirrus.com> Tested-by: Charles Keepax <ckeepax@opensource.cirrus.com> Acked-by: Chanwoo Choi <cw00.choi@samsung.com> Signed-off-by: Lee Jones <lee.jones@linaro.org>
Diffstat (limited to 'drivers/extcon')
-rw-r--r--drivers/extcon/extcon-arizona.c40
1 files 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;
}