Re: [PATCH v2] watchdog: da9062: make restart handler atomic safe

From: Stefan Lengfeld
Date: Sun Jan 19 2020 - 06:34:55 EST


Hi Marco,

On Thu, Jan 16, 2020 at 08:23:20AM +0100, Stefan Lengfeld wrote:
> On Wed, Jan 15, 2020 at 05:23:07PM +0100, Marco Felsch wrote:
> > The restart handler is executed during the shutdown phase which is
> > atomic/irq-less. The i2c framework supports atomic transfers since
> > commit 63b96983a5dd ("i2c: core: introduce callbacks for atomic
> > transfers") to address this use case. Using regmap within an atomic
> > context is allowed only if the regmap type is MMIO and the cache type
> > 'flat' or no cache is used. Using the i2c_smbus_write_byte_data()
> > function can be done without additional tests because:
> > 1) the DA9062 is an i2c-only device and
> > 2) the i2c framework emulates the smbus protocol if the host adapter
> > does not support smbus_xfer by using the master_xfer.
> >
> > Signed-off-by: Marco Felsch <m.felsch@xxxxxxxxxxxxxx>
>
> Reviewed-by: Stefan Lengfeld <contact@xxxxxxxxxxxxxxx>

Now also

Tested-by: Stefan Lengfeld <contact@xxxxxxxxxxxxxxx>

on a phyCORE-i.MX6 Quad with baseboard phyBOARD-Mira.

I'm also cc'ing Stefan from phytec, since he is also interested in the
thread/patch [1].

Kind regards,
Stefan

[1]: https://www.spinics.net/lists/linux-watchdog/msg17203.html