From: Jean Delvare <jdelvare@suse.de>
To: Heiner Kallweit <hkallweit1@gmail.com>
Cc: Andi Shyti <andi.shyti@kernel.org>,
Daniel Kurtz <djkurtz@chromium.org>,
linux-i2c@vger.kernel.org
Subject: Re: [PATCH] i2c: i801: fix potential race in i801_block_transaction_byte_by_byte
Date: Fri, 1 Sep 2023 19:26:46 +0200 [thread overview]
Message-ID: <20230901192646.3706a36c@endymion.delvare> (raw)
In-Reply-To: <d392cf3a-a029-2cd6-44e6-a98f57d42b5f@gmail.com>
On Fri, 1 Sep 2023 19:02:13 +0200, Heiner Kallweit wrote:
> On 01.09.2023 18:44, Jean Delvare wrote:
> > Hi Heiner,
> >
> > On Tue, 29 Aug 2023 08:25:23 +0200, Heiner Kallweit wrote:
> >> Currently we set SMBHSTCNT_LAST_BYTE only after the host has started
> >> receiving the last byte. If we get e.g. preempted before setting
> >> SMBHSTCNT_LAST_BYTE, the host may be finished with receiving the byte
> >> before SMBHSTCNT_LAST_BYTE is set.
> >> Therefore change the code to set SMBHSTCNT_LAST_BYTE before writing
> >> SMBHSTSTS_BYTE_DONE for the byte before the last byte. Now the code
> >> is also consistent with what we do in i801_isr_byte_done().
> >>
> >> Fixes: efa3cb15ad8b ("i2c-i801: Refactor use of LAST_BYTE in i801_block_transaction_byte_by_byte")
> >
> > I don't think this is true. This patch refactored the code but didn't
> > change the logic. The bug existed before already. As far as I see, the
> > race condition already existed when the kernel switched to git, so
> > there's no point in having a Fixes statement.
>
> Shall we go with the patch as-is or do you think it's better to resubmit
> w/o the Fixes tag?
Please resubmit, for the sake of correctness and to be fair to Daniel.
--
Jean Delvare
SUSE L3 Support
prev parent reply other threads:[~2023-09-01 17:26 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-08-29 6:25 [PATCH] i2c: i801: fix potential race in i801_block_transaction_byte_by_byte Heiner Kallweit
2023-09-01 16:44 ` Jean Delvare
2023-09-01 17:02 ` Heiner Kallweit
2023-09-01 17:26 ` Jean Delvare [this message]
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