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Message-ID: <afacba7f-c836-9d0c-3ffa-2b1cf3d4bdaa@linux.intel.com>
Date:   Thu, 27 Jul 2023 13:36:47 +0300
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Subject: Re: [PATCH v2 1/2] i2c: designware: Correct length byte validation
 logic
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To:     Tam Nguyen <tamnguyenchi@os.amperecomputing.com>,
        linux-kernel@vger.kernel.org, linux-i2c@vger.kernel.org
Cc:     patches@amperecomputing.com, andriy.shevchenko@linux.intel.com,
        mika.westerberg@linux.intel.com, jsd@semihalf.com,
        chuong@os.amperecomputing.com, darren@os.amperecomputing.com,
        Quan Nguyen <quan@os.amperecomputing.com>,
        stable@vger.kernel.org
References: <20230726080001.337353-1-tamnguyenchi@os.amperecomputing.com>
 <20230726080001.337353-2-tamnguyenchi@os.amperecomputing.com>
From:   Jarkko Nikula <jarkko.nikula@linux.intel.com>
In-Reply-To: <20230726080001.337353-2-tamnguyenchi@os.amperecomputing.com>
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On 7/26/23 11:00, Tam Nguyen wrote:
> From: Quan Nguyen <quan@os.amperecomputing.com>
> 
> Commit 0daede80f870 ("i2c: designware: Convert driver to using regmap API")
> changes the logic to validate the whole 32-bit return value of
> DW_IC_DATA_CMD register instead of 8-bit LSB without reason.
> 
> Later, commit f53f15ba5a85 ("i2c: designware: Get right data length"),
> introduced partial fix but not enough because the "tmp > 0" still test
> tmp as 32-bit value and is wrong in case the IC_DATA_CMD[11] is set.
> 
> Revert the logic to just before commit 0daede80f870
> ("i2c: designware: Convert driver to using regmap API").
> 
> Fixes: f53f15ba5a85 ("i2c: designware: Get right data length")
> Fixes: 0daede80f870 ("i2c: designware: Convert driver to using regmap API")
> Cc: stable@vger.kernel.org
> Signed-off-by: Tam Nguyen <tamnguyenchi@os.amperecomputing.com>
> Signed-off-by: Quan Nguyen <quan@os.amperecomputing.com>
> ---
>   drivers/i2c/busses/i2c-designware-master.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
> 
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>