Re: [PATCH 1/3] drm: mxsfb: Change to mxsfb-drm

From: Marek Vasut
Date: Fri Jun 15 2018 - 19:33:07 EST

On 06/16/2018 12:22 AM, Fabio Estevam wrote:
> On Fri, Jun 15, 2018 at 6:36 PM, Marek Vasut <marex@xxxxxxx> wrote:
>> Having two drivers in the kernel with different set of bugs is always bad.
> Sure, but breaking dtb's is also bad.

You picked only the first part of my argument, the less important one ;-)

> Can the mxsfb driver be modified to handle the old style bindings?

Maybe, but do we care ? Cfr my comment about the amount of users who
will be affected by this.

> The IPU drm driver is capable of handling both the old style where the
> display timing is passed in dts and the new drm style.
> For example:
> arch/arm/boot/dts/imx6qdl-sabresd.dtsi uses the drm style binding
> arch/arm/boot/dts/imx6qdl-sabreauto.dtsi uses the old style of passing
> the display timings in dts
> Both formats are accepted by the ipu drm driver.
> Can't mxsfb drm driver support both? Then we don't need to worry about
> breaking dtb's and could safely remove the mxs fbdev driver.

This might be a way forward, but again, does it justify the effort ?
We will be adding compatibility code which we will have to maintain for
maybe a handful of users I think.

Best regards,
Marek Vasut