From: Wolfram Sang <wsa+renesas@sang-engineering.com>
To: linux-i2c@vger.kernel.org
Cc: linux-renesas-soc@vger.kernel.org, Ray Jui <ray.jui@broadcom.com>,
Scott Branden <scott.branden@broadcom.com>,
Dhananjay Phadke <dphadke@linux.microsoft.com>,
bcm-kernel-feedback-list@broadcom.com,
Rayagonda Kokatanur <rayagonda.kokatanur@broadcom.com>
Subject: Re: [PATCH] i2c: rcar: avoid race when unregistering slave
Date: Fri, 31 Jul 2020 15:55:30 +0200 [thread overview]
Message-ID: <20200731135530.GC1679@kunai> (raw)
In-Reply-To: <20200726161606.15315-1-wsa+renesas@sang-engineering.com>
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On Sun, Jul 26, 2020 at 06:16:06PM +0200, Wolfram Sang wrote:
> Due to the lockless design of the driver, it is theoretically possible
> to access a NULL pointer, if a slave interrupt was running while we were
> unregistering the slave. To make this rock solid, disable the interrupt
> for a short time while we are clearing the interrupt_enable register.
> This patch is purely based on code inspection. The OOPS is super-hard to
> trigger because clearing SAR (the address) makes interrupts even more
> unlikely to happen as well. While here, reinit SCR to SDBS because this
> bit should always be set according to documentation. There is no effect,
> though, because the interface is disabled.
>
> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Applied to for-next, thanks!
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prev parent reply other threads:[~2020-07-31 13:55 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-26 16:16 [PATCH] i2c: rcar: avoid race when unregistering slave Wolfram Sang
2020-07-27 10:55 ` Niklas Söderlund
2020-07-31 13:55 ` Wolfram Sang [this message]
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