2021-02-23 09:32:12

by Yang Li

Subject: [PATCH] drivers: ipa: Add missing IRQF_ONESHOT

fixed the following coccicheck:
./drivers/net/ipa/ipa_smp2p.c:186:7-27: ERROR: Threaded IRQ with no
primary handler requested without IRQF_ONESHOT

Make sure threaded IRQs without a primary handler are always request
with IRQF_ONESHOT

Reported-by: Abaci Robot <[email protected]>
Signed-off-by: Yang Li <[email protected]>
---
drivers/net/ipa/ipa_smp2p.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ipa/ipa_smp2p.c b/drivers/net/ipa/ipa_smp2p.c
index a5f7a79..1149ed8 100644
--- a/drivers/net/ipa/ipa_smp2p.c
+++ b/drivers/net/ipa/ipa_smp2p.c
@@ -183,7 +183,7 @@ static int ipa_smp2p_irq_init(struct ipa_smp2p *smp2p, const char *name,
}
irq = ret;

- ret = request_threaded_irq(irq, NULL, handler, 0, name, smp2p);
+ ret = request_threaded_irq(irq, NULL, handler, IRQF_ONESHOT, name, smp2p);
if (ret) {
dev_err(dev, "error %d requesting \"%s\" IRQ\n", ret, name);
return ret;
--
1.8.3.1

2021-02-23 16:12:50

by Alex Elder

Subject: Re: [PATCH] drivers: ipa: Add missing IRQF_ONESHOT

On 2/23/21 3:09 AM, Yang Li wrote:
> fixed the following coccicheck:
> ./drivers/net/ipa/ipa_smp2p.c:186:7-27: ERROR: Threaded IRQ with no
> primary handler requested without IRQF_ONESHOT
>
> Make sure threaded IRQs without a primary handler are always request
> with IRQF_ONESHOT

SMP2P interrupts are handled as nested interrupts. The hard
handler for a registered SMP2P interrupt is never called, and
is in fact ignored (it should really be NULL when registering).

The "main" SMP2P interrupt handler is a ONESHOT threaded
interrupt handler, and all registered SMP2P interrupts are
handled within (called by) that main handler thread function.

It is not *necessary* to provide the IRQF_ONESHOT flag when
registering an SMP2P interrupt handler. I don't think it
does real harm to add it, but unless I'm mistaken, the
interrupt handling is actually simpler if ONESHOT is *not*
set in this case.

I could be convinced otherwise, but until I would rather
not accept this patch.

-Alex

> Reported-by: Abaci Robot <[email protected]>
> Signed-off-by: Yang Li <[email protected]>
> ---
> drivers/net/ipa/ipa_smp2p.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/ipa/ipa_smp2p.c b/drivers/net/ipa/ipa_smp2p.c
> index a5f7a79..1149ed8 100644
> --- a/drivers/net/ipa/ipa_smp2p.c
> +++ b/drivers/net/ipa/ipa_smp2p.c
> @@ -183,7 +183,7 @@ static int ipa_smp2p_irq_init(struct ipa_smp2p *smp2p, const char *name,
> }
> irq = ret;
>
> - ret = request_threaded_irq(irq, NULL, handler, 0, name, smp2p);
> + ret = request_threaded_irq(irq, NULL, handler, IRQF_ONESHOT, name, smp2p);
> if (ret) {
> dev_err(dev, "error %d requesting \"%s\" IRQ\n", ret, name);
> return ret;
>