Re: [PATCH v6 3/3] drm/xe/i2c: Keep the i2c controller always enabled
From: Heikki Krogerus
Date: Thu Jul 30 2026 - 07:11:13 EST
On Wed, Jul 29, 2026 at 05:34:26PM +0200, Raag Jadav wrote:
> On Wed, Jul 22, 2026 at 03:35:54PM +0200, Heikki Krogerus wrote:
> > Some platforms make an assumption that the i2c controller's
> > enabled state indicates also the power state of the
> > controller. This can create a problem when the controller is
> > in disabled state, because the hardware may assume
> > incorrectly that it is then also in low-power state.
> >
> > To fix this, the controller is kept enabled by taking over
> > the IC_ENABLE register. The controller has to be disabled
> > when the configuration is updated and when the target
> > address or the slave address are assigned, so disabling it
> > when IC_CON, IC_TAR or IC_SAR registers are programmed, and
> > then re-enabling it again.
> >
> > Fixes: f0e53aadd702 ("drm/xe: Support for I2C attached MCUs")
> > Cc: stable@xxxxxxxxxxxxxxx
> > Signed-off-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
>
> I'll rely on Andy and Mika's disposition on this one.
Mika should be back from vacation.
--
heikki