[PATCH v2] pinctrl: mediatek: use spin lock in mtk_rmw
From: Tzung-Bi Shih <hidden>
Date: 2021-04-19 09:35:21
Also in:
alsa-devel, linux-arm-kernel, linux-gpio
Subsystem:
pin control subsystem, pin controller - mediatek, the rest · Maintainers:
Linus Walleij, Sean Wang, Linus Torvalds
Commit 42a46434e9b1 ("pinctrl: add lock in mtk_rmw function.") uses
mutex lock in mtk_rmw. However the function is possible called from
atomic context.
For example call trace:
mutex_lock+0x28/0x64
mtk_rmw+0x38/0x80
[snip]
max98357a_daiops_trigger+0x8c/0x9c
soc_pcm_trigger+0x5c/0x10c
The max98357a_daiops_trigger() could run in either atomic or non-atomic
context. As a result, dmesg shows some similar messages: "BUG: sleeping
function called from invalid context at kernel/locking/mutex.c:254".
Uses spin lock in mtk_rmw instead.
Fixes: 42a46434e9b1 ("pinctrl: add lock in mtk_rmw function.")
Signed-off-by: Tzung-Bi Shih <redacted>
---
Changes from v1[1]:
- Snip call trace.
- Use _irqsave and _irqrestore version of spin lock.
[1]: https://patchwork.ozlabs.org/project/linux-gpio/list/?series=239749
drivers/pinctrl/mediatek/pinctrl-moore.c | 2 +-
drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c | 5 +++--
drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.h | 2 +-
drivers/pinctrl/mediatek/pinctrl-paris.c | 2 +-
4 files changed, 6 insertions(+), 5 deletions(-)
diff --git a/drivers/pinctrl/mediatek/pinctrl-moore.c b/drivers/pinctrl/mediatek/pinctrl-moore.c
index f77921957f15..3a4a23c40a71 100644
--- a/drivers/pinctrl/mediatek/pinctrl-moore.c
+++ b/drivers/pinctrl/mediatek/pinctrl-moore.c@@ -619,7 +619,7 @@ int mtk_moore_pinctrl_probe(struct platform_device *pdev, hw->nbase = hw->soc->nbase_names; - mutex_init(&hw->lock); + spin_lock_init(&hw->lock); /* Copy from internal struct mtk_pin_desc to register to the core */ pins = devm_kmalloc_array(&pdev->dev, hw->soc->npins, sizeof(*pins),
diff --git a/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c b/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c
index fcf7c3eeee4a..fc79b3a7a188 100644
--- a/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c
+++ b/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c@@ -57,15 +57,16 @@ static u32 mtk_r32(struct mtk_pinctrl *pctl, u8 i, u32 reg) void mtk_rmw(struct mtk_pinctrl *pctl, u8 i, u32 reg, u32 mask, u32 set) { u32 val; + unsigned long flags; - mutex_lock(&pctl->lock); + spin_lock_irqsave(&pctl->lock, flags); val = mtk_r32(pctl, i, reg); val &= ~mask; val |= set; mtk_w32(pctl, i, reg, val); - mutex_unlock(&pctl->lock); + spin_unlock_irqrestore(&pctl->lock, flags); } static int mtk_hw_pin_field_lookup(struct mtk_pinctrl *hw,
diff --git a/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.h b/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.h
index 65eac708a3b3..13836bb188b7 100644
--- a/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.h
+++ b/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.h@@ -252,7 +252,7 @@ struct mtk_pinctrl { struct mtk_pinctrl_group *groups; const char **grp_names; /* lock pin's register resource to avoid multiple threads issue*/ - struct mutex lock; + spinlock_t lock; }; void mtk_rmw(struct mtk_pinctrl *pctl, u8 i, u32 reg, u32 mask, u32 set);
diff --git a/drivers/pinctrl/mediatek/pinctrl-paris.c b/drivers/pinctrl/mediatek/pinctrl-paris.c
index 48e823f6d293..85db2e4377f0 100644
--- a/drivers/pinctrl/mediatek/pinctrl-paris.c
+++ b/drivers/pinctrl/mediatek/pinctrl-paris.c@@ -970,7 +970,7 @@ int mtk_paris_pinctrl_probe(struct platform_device *pdev, hw->nbase = hw->soc->nbase_names; - mutex_init(&hw->lock); + spin_lock_init(&hw->lock); err = mtk_pctrl_build_state(pdev); if (err) {
--
2.31.1.368.gbe11c130af-goog
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