[PATCH v3] drm/bridge/sii902x: Fix EDID readback

[Boris Brezillon]

On Thu, 15 Nov 2018 11:13:52 +0100
Linus Walleij <linus.walleij at linaro.org> wrote:

> On Tue, Nov 6, 2018 at 12:52 PM Fabrizio Castro
> <fabrizio.castro at bp.renesas.com> wrote:
> 
> > While adding SiI9022A support to the iwg23s board, it came
> > up that when the HDMI transmitter is in pass through mode the
> > device is not compliant with the I2C specification anymore,
> > as it requires a far bigger tbuf, due to a delay the HDMI
> > transmitter is adding when relaying the STOP condition on the
> > monitor i2c side of things.
> >
> > When not providing an appropriate delay after the STOP condition
> > the i2c bus would get stuck. Also, any other traffic on the bus
> > while talking to the monitor may cause the transaction to fail
> > or even cause issues with the i2c bus as well.
> >
> > I2c-gates seemed to reach consent as a possible way to address
> > these issues, and as such this patch is implementing a solution
> > based on that. Since others are clearly relying on the current
> > implementation of the driver, this patch won't require any DT
> > changes.
> >
> > Since we don't want any interference during the DDC Bus
> > Request/Grant procedure and while talking to the monitor, we
> > have to use the adapter locking primitives rather than the
> > i2c-mux locking primitives.
> >
> > Signed-off-by: Fabrizio Castro <fabrizio.castro at bp.renesas.com>
> >
> > ---
> > v2->v3:
> > * Incorporated comments from Boris Brezillon and Peter Rosin  
> 
> Acked-by: Linus Walleij <linus.walleij at linaro.org>
> 
> Do you need help to apply this to drm-misc or do you
> have commit access?

I can do it if needed.