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Date:   Thu, 17 Sep 2020 17:45:32 +0300
From:   Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To:     Jarkko Nikula <jarkko.nikula@linux.intel.com>
Cc:     Sultan Alsawaf <sultan@kerneltoast.com>, linux-i2c@vger.kernel.org,
        jikos@kernel.org, aaron.ma@canonical.com, admin@kryma.net,
        benjamin.tissoires@redhat.com, hdegoede@redhat.com,
        hn.chen@weidahitech.com, kai.heng.feng@canonical.com,
        linux-input@vger.kernel.org, linux-kernel@vger.kernel.org,
        mika.westerberg@linux.intel.com, vicamo.yang@canonical.com,
        wsa@kernel.org
Subject: Re: [PATCH v2 2/4] i2c: designware: Ensure tx_buf_len is nonzero for
 SMBus block reads
Message-ID: <20200917144532.GO3956970@smile.fi.intel.com>
References: <20200917052256.5770-1-sultan@kerneltoast.com>
 <20200917052256.5770-3-sultan@kerneltoast.com>
 <4698b23c-7af6-3f44-975d-b1f692ae3f00@linux.intel.com>
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On Thu, Sep 17, 2020 at 04:44:18PM +0300, Jarkko Nikula wrote:
> On 9/17/20 8:22 AM, Sultan Alsawaf wrote:
> > From: Sultan Alsawaf <sultan@kerneltoast.com>
> > 
> > The point of adding a byte to len in i2c_dw_recv_len() is to make sure
> > that tx_buf_len is nonzero, so that i2c_dw_xfer_msg() can let the i2c
> > controller know that the i2c transaction can end. Otherwise, the i2c
> > controller will think that the transaction can never end for block
> > reads, which results in the stop-detection bit never being set and thus
> > the transaction timing out.
> > 
> > Adding a byte to len is not a reliable way to do this though; sometimes
> > it lets tx_buf_len become zero, which results in the scenario described
> > above. Therefore, just directly ensure tx_buf_len cannot be zero to fix
> > the issue.
> > 
> > Fixes: c3ae106050b9 ("i2c: designware: Implement support for SMBus block read and write")
> > Signed-off-by: Sultan Alsawaf <sultan@kerneltoast.com>
> > ---
> >   drivers/i2c/busses/i2c-designware-master.c | 5 +++--
> >   1 file changed, 3 insertions(+), 2 deletions(-)
> > 
> Were other patches in series dropped somewhere? I received only this.

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-- 
With Best Regards,
Andy Shevchenko