From: Alex Elder <elder@ieee.org>
To: Yang Li <yang.lee@linux.alibaba.com>, elder@kernel.org
Cc: davem@davemloft.net, kuba@kernel.org, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] drivers: ipa: Add missing IRQF_ONESHOT
Date: Tue, 23 Feb 2021 10:05:35 -0600 [thread overview]
Message-ID: <d57e0a43-4d87-93cf-471c-c8185ea85ced@ieee.org> (raw)
In-Reply-To: <1614071362-123210-1-git-send-email-yang.lee@linux.alibaba.com>
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 <abaci@linux.alibaba.com>
> Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
> ---
> 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;
>
prev parent reply other threads:[~2021-02-23 16:06 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-23 9:09 [PATCH] drivers: ipa: Add missing IRQF_ONESHOT Yang Li
2021-02-23 16:05 ` Alex Elder [this message]
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