Re: [PATCH v1] i2c: lpi2c: implement master_xfer_atomic callback

[Emanuele Ghidoli]

On 11/04/2025 13:55, Carlos Song wrote:
>> On Wed, Mar 19, 2025 at 03:51:14PM +0100, Francesco Dolcini wrote:
>>> From: Emanuele Ghidoli <emanuele.ghidoli@xxxxxxxxxxx>
>>>
>>> Rework the read and write code paths in the driver to support
>>> operation in atomic contexts. To achieve this, the driver must not
>>> rely on IRQs or perform any scheduling, e.g., via a sleep or schedule
>>> routine. Even jiffies do not advance in atomic contexts, so timeouts
>>> based on them are substituted with delays.
>>>
>>> Implement atomic, sleep-free, and IRQ-less operation. This increases
>>> complexity but is necessary for atomic I2C transfers required by some
>>> hardware configurations, e.g., to trigger reboots on an external PMIC chip.
>>>
>>> Signed-off-by: Emanuele Ghidoli <emanuele.ghidoli@xxxxxxxxxxx>
>>> Signed-off-by: Francesco Dolcini <francesco.dolcini@xxxxxxxxxxx>
>>
>> Any comment on this?
> Looks good. Thank you for your work!
> Do you test it at some board? How can we test simply?

We tested it also by using the xfer_atomic for "normal" transfers
(.master_xfer = lpi2c_imx_xfer_atomic).
The driver is used to drive multiple buses with different devices.

Emanuele