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

Marek Vasut
2018-07-12T13:14:57Z

On 07/12/2018 03:03 PM, Leonard Crestez wrote:
> On Thu, 2018-07-12 at 11:21 +0200, Stefan Agner wrote:
>> On 10.07.2018 11:11, Marek Vasut wrote:
>>> On 07/10/2018 11:06 AM, Stefan Agner wrote:
>>>> This is one of the situation where states quo is kinda the worst
>>>> situation.
>>>>
>>>> Currently imx_v6_v7_defconfig and mxs_defconfig actually still uses
>>>> CONFIG_FB_MXS.
>>>>
>>>> I understand that you'd rather prefer to move forward. I suggest we do
>>>> it in steps.
>>>>
>>>> In 4.19:
>>>>
>>>> - Change DRM driver.name to mxsfb-drm so we avoid conflicts for now
>>>
>>> But this will break mesa if it depends on mxsfb name for ie. etnaviv
>>> binding.
>>
>> Does it? grep -r -e mxsfb in libdrm and mesa master returns nothing.
>>
>> There is also .name in struct drm_driver, which is already set to
>> mxsfb-drm... Is that the one exposed to user space?
>
> Running etnaviv+x11 with a renamed mxsfb driver works fine on imx6sx-
> sdb.
>
> Tools like modetest already need -M mxsfb-drm, the drm_driver.name
> seems to be what matters.
>
>> - Remove CONFIG_FB_MXS from imx_v6_v7_defconfig/mxs_defconfig now, and
>> only enable CONFIG_DRM_MXSFB=y
>
> If one of the drivers is renamed then they can coexist: since the
> bindings are distinct one driver will return a probe error and the
> other will bind successfully. This can even be adjusted so that it
> doesn't even print ugly scary errors.
>
> This can last until somebody implements support for old bindings in the
> drm driver and then FB_MXS can just be deleted.

So why don't we just convert the DT bindings on boards supported
upstream and zap the old driver ? What is the problem with that?

Realistically, how many MXS boards in the field use old DT and new kernel ?

--
Best regards,
Marek Vasut