Re: [PATCH v2 0/6] i2c: xiic: Fix broken locking

Michal Simek
2021-08-27T08:34:19Z

On 8/27/21 10:31 AM, Raviteja Narayanam wrote:
>
>
>> -----Original Message-----
>> From: Michal Simek <michal.simek@xilinx.com>
>> Sent: Tuesday, August 24, 2021 12:29 PM
>> To: Marek Vasut <marex@denx.de>; linux-i2c@vger.kernel.org; Raviteja
>> Narayanam <rna@xilinx.com>
>> Cc: Michal Simek <michals@xilinx.com>; Shubhrajyoti Datta
>> <shubhraj@xilinx.com>; Wolfram Sang <wsa@kernel.org>
>> Subject: Re: [PATCH v2 0/6] i2c: xiic: Fix broken locking
>>
>> +ravi
>>
>> On 8/23/21 11:41 PM, Marek Vasut wrote:
>>> Booting ZynqMP with XIIC I2C driver shows multitude of race conditions
>>> in the XIIC driver. This is because locking is completely missing from
>>> the driver, and there are odd corner cases where the hardware behaves
>>> strangely.
>>>
>>> Most of these races could be triggered easily when booting on SMP
>>> machines, like the ZynqMP which has up to 4 cores. It is sufficient
>>> for the interrupt handler to run on another core than xiic_start_xfer
>>> and the driver fails completely.
>>>
>>> This does not add support for long transfers, this only fixes the
>>> driver to be usable at all instead of being completely broken.
>>>
>>> The V2 fixes a few remaining details which cropped up in deployment
>>> over the last year or so, so I believe the result should be reasonably
>>> well tested.
>
> Thanks a lot for the patches, Marek.
> I have tested these on our boards and they are working fine.
>
> I will rebase my patch series on top of this and send after rc1.

Wolfram: Can you please merge this series? Ravi's series will come on
the top of this one.

Acked-by: Michal Simek <michal.simek@xilinx.com>

Thanks,
Michal