Re: [PATCH v2 11/11] mt9m111: make use of testpattern

[Robert Jarzmik <robert.jarzmik@free.fr>]

Guennadi Liakhovetski <g.liakhovetski@gmx.de> writes:

> Yes, but this has another disadvantage - if you do not use s_register / 
> g_register, maybe you just have CONFIG_VIDEO_ADV_DEBUG off, then, once you 
> load the module with the testpattern parameter, you cannot switch using 
> testpatterns off again (without a reboot or a power cycle). With the 
> original version you can load the driver with the parameter set, then 
> unload it, load it without the parameter and testpattern would be cleared. 
> In general, I think, using direct register access is discouraged, 
> especially if there's a way to set the same functionality using driver's 
> supported interfaces.

I agree. If there is a way without debug registers, let's use it.

> Hm, if I'm not mistaken, it has once been mentioned, that these test-patterns
> can be nicely implemented using the S_INPUT ioctl(). Am I right? How about
> that? But we'd need a confirmation for that, I'm not 100% sure.
I can't remember that. But if there is a standard ioctl (as seems to show
videodev2.h), and that its use could mean "camera's input is a testpattern" or
"camera input is the normal optical flow", then we should use it.
If not, the old way with debug registers is the only alternative I see without
having to unload/reload the module (if it's a module and not statically embedded
in the kernel).

Cheers.

--
Robert