From: Sumit Garg <sumit.garg@linaro.org> To: Arnd Bergmann <arnd@arndb.de>, "hasegawa-hitomi@fujitsu.com" <hasegawa-hitomi@fujitsu.com> Cc: "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>, "jirislaby@kernel.org" <jirislaby@kernel.org>, Linux ARM <linux-arm-kernel@lists.infradead.org>, SoC Team <soc@kernel.org>, Olof Johansson <olof@lixom.net>, Catalin Marinas <catalin.marinas@arm.com>, Will Deacon <will@kernel.org> Subject: Re: [PATCH] soc: fujitsu: Add A64FX diagnostic interrupt driver Date: Mon, 28 Feb 2022 13:35:44 +0530 [thread overview] Message-ID: <CAFA6WYMqO9rnHaYgyrY=+zV9saS1jrayiVoB_FwSm_yCBRhu5g@mail.gmail.com> (raw) In-Reply-To: <CAK8P3a0T1eP9a_1UhYRg0wHBsjyLLORoKB+44PAPM4zj3ryVcA@mail.gmail.com> Hi Arnd, Hitomi, On Fri, 25 Feb 2022 at 16:50, Arnd Bergmann <arnd@arndb.de> wrote: > > On Fri, Feb 25, 2022 at 11:35 AM hasegawa-hitomi@fujitsu.com > <hasegawa-hitomi@fujitsu.com> wrote: > > > > Hi Greg and Jiri, > > > > I'm trying to implement a feature for A64FX that will panic when > > a diagnostic interrupt is received. > > Arnd suggested that handle_sysrq() should be used > > but I'm wonderingif it's ok to call it in NMI. > > Would you please let me know if we can call handle_sysrq() in NMI? > > I see some work from Sumit Garg to make it possible, but this was never > merged, so presumably it is not safe: > > https://lore.kernel.org/linux-arm-kernel/CAFA6WYOWHgmYYt=KGXDh2hKiuy_rQbJfi279ev0+s-Qh7L21kA@mail.gmail.com/t/#m2b5006f08581448020eb24566927a104d0b95c44 > Yeah it had some tricky bits but it wasn't the reason for the work being stalled. Actually it turned out to be cumbersome to allow all 8250 UARTs to be driven from NMI interrupts as well. But given this special diagnostic interrupt on A64FX turned as pseudo NMI, it shouldn't be that hard to test it with this [1] minimal patch. [1] https://lkml.org/lkml/2022/2/28/83 -Sumit > Sumit has worked on some related areas as well, and may have additional > ideas for you. > > Arnd
WARNING: multiple messages have this Message-ID (diff)
From: Sumit Garg <sumit.garg@linaro.org> To: Arnd Bergmann <arnd@arndb.de>, "hasegawa-hitomi@fujitsu.com" <hasegawa-hitomi@fujitsu.com> Cc: "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>, "jirislaby@kernel.org" <jirislaby@kernel.org>, Linux ARM <linux-arm-kernel@lists.infradead.org>, SoC Team <soc@kernel.org>, Olof Johansson <olof@lixom.net>, Catalin Marinas <catalin.marinas@arm.com>, Will Deacon <will@kernel.org> Subject: Re: [PATCH] soc: fujitsu: Add A64FX diagnostic interrupt driver Date: Mon, 28 Feb 2022 13:35:44 +0530 [thread overview] Message-ID: <CAFA6WYMqO9rnHaYgyrY=+zV9saS1jrayiVoB_FwSm_yCBRhu5g@mail.gmail.com> (raw) In-Reply-To: <CAK8P3a0T1eP9a_1UhYRg0wHBsjyLLORoKB+44PAPM4zj3ryVcA@mail.gmail.com> Hi Arnd, Hitomi, On Fri, 25 Feb 2022 at 16:50, Arnd Bergmann <arnd@arndb.de> wrote: > > On Fri, Feb 25, 2022 at 11:35 AM hasegawa-hitomi@fujitsu.com > <hasegawa-hitomi@fujitsu.com> wrote: > > > > Hi Greg and Jiri, > > > > I'm trying to implement a feature for A64FX that will panic when > > a diagnostic interrupt is received. > > Arnd suggested that handle_sysrq() should be used > > but I'm wonderingif it's ok to call it in NMI. > > Would you please let me know if we can call handle_sysrq() in NMI? > > I see some work from Sumit Garg to make it possible, but this was never > merged, so presumably it is not safe: > > https://lore.kernel.org/linux-arm-kernel/CAFA6WYOWHgmYYt=KGXDh2hKiuy_rQbJfi279ev0+s-Qh7L21kA@mail.gmail.com/t/#m2b5006f08581448020eb24566927a104d0b95c44 > Yeah it had some tricky bits but it wasn't the reason for the work being stalled. Actually it turned out to be cumbersome to allow all 8250 UARTs to be driven from NMI interrupts as well. But given this special diagnostic interrupt on A64FX turned as pseudo NMI, it shouldn't be that hard to test it with this [1] minimal patch. [1] https://lkml.org/lkml/2022/2/28/83 -Sumit > Sumit has worked on some related areas as well, and may have additional > ideas for you. > > Arnd _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2022-02-28 8:05 UTC|newest] Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-02-18 9:20 [PATCH] soc: fujitsu: Add A64FX diagnostic interrupt driver Hitomi Hasegawa 2022-02-18 9:20 ` Hitomi Hasegawa 2022-02-18 10:35 ` Arnd Bergmann 2022-02-18 10:35 ` Arnd Bergmann 2022-02-22 10:52 ` hasegawa-hitomi 2022-02-22 10:52 ` hasegawa-hitomi 2022-02-25 10:35 ` hasegawa-hitomi 2022-02-25 10:35 ` hasegawa-hitomi 2022-02-25 10:51 ` gregkh 2022-02-25 10:51 ` gregkh 2022-02-25 11:20 ` Arnd Bergmann 2022-02-25 11:20 ` Arnd Bergmann 2022-02-28 8:05 ` Sumit Garg [this message] 2022-02-28 8:05 ` Sumit Garg 2022-02-28 8:51 ` hasegawa-hitomi 2022-02-28 8:51 ` hasegawa-hitomi
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to='CAFA6WYMqO9rnHaYgyrY=+zV9saS1jrayiVoB_FwSm_yCBRhu5g@mail.gmail.com' \ --to=sumit.garg@linaro.org \ --cc=arnd@arndb.de \ --cc=catalin.marinas@arm.com \ --cc=gregkh@linuxfoundation.org \ --cc=hasegawa-hitomi@fujitsu.com \ --cc=jirislaby@kernel.org \ --cc=linux-arm-kernel@lists.infradead.org \ --cc=olof@lixom.net \ --cc=soc@kernel.org \ --cc=will@kernel.org \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.