From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3C0122FFDE0; Wed, 12 Nov 2025 09:50:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762941028; cv=none; b=de6/GxKzQt05ObQAOyzQpnGInJw/0hStdkB2NryoJcbRFPZHWtVVxGtcH2HEh+NW6b3VmhPI+PYGJarVWOPUXQJNyrNV8DAmYwrhtv+zqOmdTtkWOFAgW1FRoPKKUXzfjxG4m3mwoY5CtFmYSnvP8kUM9L6muo9IoUCMBYc+bU0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762941028; c=relaxed/simple; bh=wKkYTwbaHODjzCytHEFDqnL5g4JxssRcsrQb6AjyIG4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=s8XrxaaQ8OQxhXHF+qBUbqo9T7Tk605KnWJqcEYvMizxmxJlDSsrcMQ0Zg0MtmzHafmkH1hBgejFr1+Tc83V2wMXOssWc1ON+aW8fqwgbjuGkRLW1ThhNS/LkTC97gKzUe2B64JOVe85+PQqGyTOsellI/jB+AsU3QaJtlG+Hpo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=THXlsGbF; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="THXlsGbF" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AE0C7C4CEF8; Wed, 12 Nov 2025 09:50:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1762941027; bh=wKkYTwbaHODjzCytHEFDqnL5g4JxssRcsrQb6AjyIG4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=THXlsGbFErwUFo1wXBwnqtZVc6BeYn6L2UE7CtZWfMJ4+KHQIlHtuc0TildUHh9Ob lbTpx2tKz/MJDGXzxMH3yv/POWUQ2aqZzG7HA94ie+/hvHaVTkNs0qr3mkXqf8MUl6 3xQrouYjCT1oIZFDzLeMNz2k5X4HgsMojIK8wtRmO6zaaZSfFJSKTvA/atntB+Nvce UTg4ZNmTK0FKQW5hAT0TVEXQQv998uAJgquRdnYwTccyPWKJ4vmwWzDuutaq7NLM3K yO9dpZI9D2EUC6PxhSTPniAIx6r42xtWyAYBzgMBzkGIU3Q09/XJ3yR3XEsaBgw3Vc GTO/aG2ppFgmw== Date: Wed, 12 Nov 2025 10:50:19 +0100 From: Lorenzo Pieralisi To: Charles Mirabile Cc: fj1078ii@fujitsu.com, catalin.marinas@arm.com, fj2767dz@fujitsu.com, guohanjun@huawei.com, ilkka@os.amperecomputing.com, lenb@kernel.org, linux-acpi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, rafael@kernel.org, sudeep.holla@arm.com, will@kernel.org, tglx@linutronix.de, maz@kernel.org Subject: Re: [PATCH v4] ACPI: AGDI: Add interrupt signaling mode support Message-ID: References: <20251112044239.4049011-1-cmirabil@redhat.com> Precedence: bulk X-Mailing-List: linux-acpi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20251112044239.4049011-1-cmirabil@redhat.com> [+cc Thomas, Marc] On Tue, Nov 11, 2025 at 11:42:37PM -0500, Charles Mirabile wrote: > Hi All— > > On Mon, Nov 10, 2025 at 07:38:17AM +0000, Kazuhiro Abe (Fujitsu) wrote: > > Hi Will, > > > > > Hi Will, > > > > > > > [You don't often get email from will@kernel.org. Learn why this is > > > > important at https://aka.ms/LearnAboutSenderIdentification ] > > > > > > > > On Mon, Oct 20, 2025 at 09:23:05PM +0800, Hanjun Guo wrote: > > > > > On 2025/10/17 15:39, Kazuhiro Abe wrote: > > > > > > AGDI has two types of signaling modes: SDEI and interrupt. > > > > > > Currently, the AGDI driver only supports SDEI. > > > > > > Therefore, add support for interrupt signaling mode The interrupt > > > > > > vector is retrieved from the AGDI table, and call panic function > > > > > > when an interrupt occurs. > > > > > > > > > > > > Reviewed-by: Ilkka Koskinen > > > > > > Signed-off-by: Kazuhiro Abe > > > > > > --- > > > > > > Hanjun, I have addressed all your comments. > > > > > > Please review them. > > > > > > > > > > > > v3->v4 > > > > > > - Add a comment to the flags member. > > > > > > - Fix agdi_interrupt_probe. > > > > > > - Fix agdi_interrupt_remove. > > > > > > - Add space in struct initializsation. > > > > > > - Delete curly braces. > > > > > > > > > > Looks good to me, > > > > > > > > > > Acked-by: Hanjun Guo > > > > > > > > I wasn't cc'd on the original patch but I couldn't figure out why it > > > > uses IRQF_NO_AUTOEN when requesting the irq given that the first thing > > > > it does is enable it. > > > > > > I misunderstood the usage of request_irq and enable_irq. > > > Since there's no need to separate them, I will remove IRQF_NO_AUTOEN and the > > > enable_irq call, and send v5. > > > > I found out when calling request_nmi, removing IRQF_NO_AUTOEN results in an error (-EINVAL). > > Therefore, I would like to keep IRQF_NO_AUTOEN specified. > > If you have any comments on this version, please let me know. > > Could it be that this is just a bug in `request_nmi`? I see the following: > > if (!desc || (irq_settings_can_autoenable(desc) && > !(irqflags & IRQF_NO_AUTOEN)) || > !irq_settings_can_request(desc) || > WARN_ON(irq_settings_is_per_cpu_devid(desc)) || > !irq_supports_nmi(desc)) > return -EINVAL; > > Perhaps there is just a missing `!` before `irq_settings_can_autoenable`. > > As far as I can tell it has always been wrong - git blame points me to the > original commit where that code was introduced: > > b525903c254da ("genirq: Provide basic NMI management for interrupt lines") I don't think that's the right rationale (and I can't claim to understand it fully either - that's why I added Thomas/Marc in CC). As per b525903c254da - IIUC NMI must not be autoenable-capable - enable/disable must be done using enable_nmi/disable_nmi_nosync explicitly. cbe16f35bee6 ("genirq: Add IRQF_NO_AUTOEN for request_irq/nmi()") added the logic checking the IRQF_NO_AUTOEN flag to request_nmi(). Now, AFAICS irq_settings_can_autoenable(desc) returns true in this specific case - the IRQ is a GICv3 SPI. First question is - before commit cbe16f35bee6, how request_nmi() could have possibly succeeded - irq_settings_can_autoenable() would return true and request_nmi() would have failed. Come cbe16f35bee6: if (!desc || (irq_settings_can_autoenable(desc) && !(irqflags & IRQF_NO_AUTOEN)) || !irq_settings_can_request(desc) || WARN_ON(irq_settings_is_per_cpu_devid(desc)) || !irq_supports_nmi(desc)) return -EINVAL; Now the check passes _if_ you pass in irqflags IRQF_NO_AUTOEN. I agree with Will that's a bit counterintuitive - maybe we can force the irqdesc to be NOAUTOEN in request_nmi() directly ? Thomas and Marc know better so that's where I stop. Thanks, Lorenzo > I looked and the only two callers are using `IRQF_NO_AUTOEN` so I guess it > just hasn't been noticed yet. > > Happy to send a patch to fix it. > > > > > Best Regards, > > Kazuhiro Abe > > > > > > > > Best Regards, > > > Kazuhiro Abe > > > > > > > > > > > Will > > Best—Charlie >