2024-04-29 07:05:48

by Jim Liu

Subject: [PATCH v3] gpio: nuvoton: Fix sgpio irq handle error

The generic_handle_domain_irq() function calls irq_resolve_mapping()
so calling irq_find_mapping() is duplicative and will lead to a stack
trace and an RCU stall.


Fixes: c4f8457d17ce ("gpio: nuvoton: Add Nuvoton NPCM sgpio driver")
Signed-off-by: Jim Liu <[email protected]>
---
Changes for v3:
- remove unused variable
Changes for v2:
- add more description
---
drivers/gpio/gpio-npcm-sgpio.c | 10 ++++------
1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/drivers/gpio/gpio-npcm-sgpio.c b/drivers/gpio/gpio-npcm-sgpio.c
index d31788b43abc..260570614543 100644
--- a/drivers/gpio/gpio-npcm-sgpio.c
+++ b/drivers/gpio/gpio-npcm-sgpio.c
@@ -434,7 +434,7 @@ static void npcm_sgpio_irq_handler(struct irq_desc *desc)
struct gpio_chip *gc = irq_desc_get_handler_data(desc);
struct irq_chip *ic = irq_desc_get_chip(desc);
struct npcm_sgpio *gpio = gpiochip_get_data(gc);
- unsigned int i, j, girq;
+ unsigned int i, j;
unsigned long reg;

chained_irq_enter(ic, desc);
@@ -443,11 +443,9 @@ static void npcm_sgpio_irq_handler(struct irq_desc *desc)
const struct npcm_sgpio_bank *bank = &npcm_sgpio_banks[i];

reg = ioread8(bank_reg(gpio, bank, EVENT_STS));
- for_each_set_bit(j, &reg, 8) {
- girq = irq_find_mapping(gc->irq.domain,
- i * 8 + gpio->nout_sgpio + j);
- generic_handle_domain_irq(gc->irq.domain, girq);
- }
+ for_each_set_bit(j, &reg, 8)
+ generic_handle_domain_irq(gc->irq.domain,
+ i * 8 + gpio->nout_sgpio + j);
}

chained_irq_exit(ic, desc);
--
2.34.1

2024-05-03 08:36:52

by Linus Walleij

Subject: Re: [PATCH v3] gpio: nuvoton: Fix sgpio irq handle error

On Mon, Apr 29, 2024 at 9:05 AM Jim Liu <[email protected]> wrote:

> The generic_handle_domain_irq() function calls irq_resolve_mapping()
> so calling irq_find_mapping() is duplicative and will lead to a stack
> trace and an RCU stall.
>
>
> Fixes: c4f8457d17ce ("gpio: nuvoton: Add Nuvoton NPCM sgpio driver")
> Signed-off-by: Jim Liu <[email protected]>

Reviewed-by: Linus Walleij <[email protected]>

Yours,
Linus Walleij

2024-05-03 11:56:50

by Dan Carpenter

Subject: Re: [PATCH v3] gpio: nuvoton: Fix sgpio irq handle error

On Mon, Apr 29, 2024 at 03:05:23PM +0800, Jim Liu wrote:
> The generic_handle_domain_irq() function calls irq_resolve_mapping()
> so calling irq_find_mapping() is duplicative and will lead to a stack
> trace and an RCU stall.
>
>
> Fixes: c4f8457d17ce ("gpio: nuvoton: Add Nuvoton NPCM sgpio driver")
> Signed-off-by: Jim Liu <[email protected]>
> ---
> Changes for v3:
> - remove unused variable
> Changes for v2:
> - add more description

Thanks!

Reviewed-by: Dan Carpenter <[email protected]>

regards,
dan carpenter

2024-05-03 16:37:53

by Markus Elfring

Subject: Re: [PATCH v3] gpio: nuvoton: Fix sgpio irq handle error

> The generic_handle_domain_irq() function calls irq_resolve_mapping()
> so calling irq_find_mapping() is duplicative and will lead to a stack
> trace and an RCU stall.

Can a wording approach (like the following) be a bit nicer?

The generic_handle_domain_irq() function calls irq_resolve_mapping().
Thus delete a duplicative irq_find_mapping() call
so that a stack trace and an RCU stall will be avoided.


Regards,
Markus