Re: 答复: [RESEND 1/3] drm: fsl-dcu: Fix no fb check bug

[Stefan Agner]

On 2016-01-01 07:10, Daniel Stone wrote:
> Hi,
> 
> On 30 December 2015 at 07:37, Meng Yi <meng.yi at nxp.com> wrote:
>> I have tested your patch, It seems good to me.
>> But I think state->fb check is still necessary, because fb is related to crtc , and panel is related to connector,. When fsl,panel is not valid, it indicate that connector is not available, but fb check is still needed. But I am not so sure, and what do you think?
> 
> fb is tied to planes. Planes are tied to CRTCs. CRTCs are tied to
> connectors. Connectors are tied to the panel. If the panel is not
> found, no connectors will be activated, so no CRTCs will be enabled,
> so no planes will be enabled.
> 
> Please let me be very clear though: setting fb == NULL is legitimate.
> Userspace may do this at any time. Crashing when plane->state->fb ==
> NULL is an error in your driver and must be fixed.

Thanks for this clarification. Ok, I agree the patch is needed despite
my fix then...

Acked-by: Stefan Agner <stefan at agner.ch>

--
Stefan