Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
MIME-Version: 1.0
References: <20220803185910.5jpufgziqsslnqtf@pengutronix.de>
 <20220804064803.63157-1-sebastian.wuerl@ororatech.com> <20220804070603.s3llvccpldtkejln@pengutronix.de>
In-Reply-To: <20220804070603.s3llvccpldtkejln@pengutronix.de>
From:   =?UTF-8?Q?Sebastian_W=C3=BCrl?= <sebastian.wuerl@ororatech.com>
Date:   Thu, 4 Aug 2022 09:45:07 +0200
Message-ID: <CA+KjhYWukGxZUMMch_vFe=TNYCD0-jmuwO2520oUVDPE2kE1Rw@mail.gmail.com>
Subject: Re: [PATCH] can: mcp251x: Fix race condition on receive interrupt
To:     Marc Kleine-Budde <mkl@pengutronix.de>
Cc:     Wolfgang Grandegger <wg@grandegger.com>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Vincent Mailhol <mailhol.vincent@wanadoo.fr>,
        =?UTF-8?Q?Stefan_M=C3=A4tje?= <stefan.maetje@esd.eu>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        Oliver Hartkopp <socketcan@hartkopp.net>,
        Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
        =?UTF-8?Q?Uwe_Kleine=2DK=C3=B6nig?= 
        <u.kleine-koenig@pengutronix.de>,
        Christian Pellegrin <chripell@fsfe.org>,
        linux-can@vger.kernel.org, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

On Thu, Aug 4, 2022 at 9:06 AM Marc Kleine-Budde <mkl@pengutronix.de> wrote:
>
> Another optimization idea: Do we need to re-read the eflag1? "eflag" is
> for error handling only and you're optimizing the good path.

I'd argue if a new message entered mailbox 1, this also potentially
changed the error state, so we need to read it.

Thanks a lot for your feedback! Will post v3 soon.

Also I'm sorry for spam in anyones inbox, I didn't get my mailing
program to produce plain-text for the last mail.

best,
Sebastian