| Message ID | 20210419093449.3125704-1-tzungbi@google.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] pinctrl: mediatek: use spin lock in mtk_rmw | expand |
On Mon, Apr 19, 2021 at 11:35 AM Tzung-Bi Shih <tzungbi@google.com> wrote: > 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 <tzungbi@google.com> Pulled out v1 and applied this v2 instead, thanks! Yours, Linus Walleij
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) {
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 <tzungbi@google.com> --- 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(-)