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

[Linus Walleij]

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?

Yours,
Linus Walleij