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

Michal Simek
2021-09-14T11:54:47Z

On 9/14/21 12:29 PM, Wolfram Sang wrote:
> On Mon, Aug 23, 2021 at 11:41:39PM +0200, 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.
>>
>> Marek Vasut (6):
>> i2c: xiic: Fix broken locking on tx_msg
>> i2c: xiic: Drop broken interrupt handler
>> i2c: xiic: Defer xiic_wakeup() and __xiic_start_xfer() in
>> xiic_process()
>> i2c: xiic: Switch from waitqueue to completion
>> i2c: xiic: Only ever transfer single message
>> i2c: xiic: Fix RX IRQ busy check
>>
>
> Applied to for-next, thanks everyone!
>

Thx.
FYI: Ravi will be sending his series on the top of this one.

Thanks,
Michal