On Mon, Jan 15, 2024 at 11:50:52AM +0300, Dan Carpenter wrote: > Hello Bartosz Golaszewski, > > The patch 65a828bab158: "gpiolib: use a mutex to protect the list of > GPIO devices" from Dec 15, 2023 (linux-next), leads to the following > Smatch static checker warning: > > drivers/net/wireless/ath/ath9k/hw.c:2836 ath9k_hw_gpio_get() > warn: sleeping in atomic context > > drivers/net/wireless/ath/ath9k/hw.c > 2826 val = MS_REG_READ(AR9285, gpio); > 2827 else if (AR_SREV_9280(ah)) > 2828 val = MS_REG_READ(AR928X, gpio); > 2829 else if (AR_DEVID_7010(ah)) > 2830 val = REG_READ(ah, AR7010_GPIO_IN) & BIT(gpio); > 2831 else if (AR_SREV_9300_20_OR_LATER(ah)) > 2832 val = REG_READ(ah, AR_GPIO_IN(ah)) & BIT(gpio); > 2833 else > 2834 val = MS_REG_READ(AR, gpio); > 2835 } else if (BIT(gpio) & ah->caps.gpio_requested) { > --> 2836 val = gpio_get_value(gpio) & BIT(gpio); > ^^^^^^^^^^^^^^ > > 2837 } else { > 2838 WARN_ON(1); > 2839 } > 2840 > 2841 return !!val; > 2842 } > > Before gpio_get_value() took a spinlock but now it takes a mutex > (actually a rw semaphor now). The call tree where we are in atomic > context is: > > ath_btcoex_period_timer() <- disables preempt > -> ath_detect_bt_priority() > -> ath9k_hw_gpio_get() > > Another warning this change causes is: > > drivers/input/keyboard/matrix_keypad.c:95 enable_row_irqs() warn: sleeping in atomic context > matrix_keypad_scan() <- disables preempt > -> enable_row_irqs() > > drivers/input/keyboard/matrix_keypad.c:108 disable_row_irqs() warn: sleeping in atomic context > matrix_keypad_interrupt() <- disables preempt > -> disable_row_irqs() Now that that operation becomes heavier we should convert row GPIOs into interrupt numbers in probe() and then this issue will go away. Thanks. -- Dmitry