From: Taiping Lai taiping.lai@unisoc.com
[ Upstream commit 5fcface659aab7eac4bd65dd116d98b8f7bb88d5 ]
The raw interrupt status of GPIO maybe set before the interrupt is enabled, which would trigger the interrupt event once enabled it from user side. This is the case for edge interrupts only. Adding a clear operation when setting interrupt type can avoid that.
There're a few considerations for the solution: 1) This issue is for edge interrupt only; The interrupts requested by users are IRQ_TYPE_LEVEL_HIGH as default, so clearing interrupt when request is useless. 2) The interrupt type can be set to edge when request and following up with clearing it though, but the problem is still there once users set the interrupt type to level trggier. 3) We can add a clear operation after each time of setting interrupt enable bit, but it is redundant for level trigger interrupt.
Therefore, the solution is this patch seems the best for now.
Fixes: 9a3821c2bb47 ("gpio: Add GPIO driver for Spreadtrum SC9860 platform") Signed-off-by: Taiping Lai taiping.lai@unisoc.com Signed-off-by: Chunyan Zhang chunyan.zhang@unisoc.com Reviewed-by: Baolin Wang baolin.wang7@gmail.com Signed-off-by: Bartosz Golaszewski bgolaszewski@baylibre.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpio/gpio-sprd.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/gpio/gpio-sprd.c b/drivers/gpio/gpio-sprd.c index 55072d2b367fa..4d53347adcafa 100644 --- a/drivers/gpio/gpio-sprd.c +++ b/drivers/gpio/gpio-sprd.c @@ -149,17 +149,20 @@ static int sprd_gpio_irq_set_type(struct irq_data *data, sprd_gpio_update(chip, offset, SPRD_GPIO_IS, 0); sprd_gpio_update(chip, offset, SPRD_GPIO_IBE, 0); sprd_gpio_update(chip, offset, SPRD_GPIO_IEV, 1); + sprd_gpio_update(chip, offset, SPRD_GPIO_IC, 1); irq_set_handler_locked(data, handle_edge_irq); break; case IRQ_TYPE_EDGE_FALLING: sprd_gpio_update(chip, offset, SPRD_GPIO_IS, 0); sprd_gpio_update(chip, offset, SPRD_GPIO_IBE, 0); sprd_gpio_update(chip, offset, SPRD_GPIO_IEV, 0); + sprd_gpio_update(chip, offset, SPRD_GPIO_IC, 1); irq_set_handler_locked(data, handle_edge_irq); break; case IRQ_TYPE_EDGE_BOTH: sprd_gpio_update(chip, offset, SPRD_GPIO_IS, 0); sprd_gpio_update(chip, offset, SPRD_GPIO_IBE, 1); + sprd_gpio_update(chip, offset, SPRD_GPIO_IC, 1); irq_set_handler_locked(data, handle_edge_irq); break; case IRQ_TYPE_LEVEL_HIGH: