Improvements for the PS3

[Geoff Levand]

Hi Fredrik,

On 07/14/2018 09:49 AM, Fredrik Noring wrote:
> so I added a sleep with
> 
> +	msleep(10000);
> +
>  	return 0;
> 
> et voilà, the screen came alive and the kernel panic was revealed! It seems
> the kernel panics so fast that the PS3 frame buffer is unprepared. This is,
> of course, very unfortunate because trying to debug the boot process without
> a screen or any other means of obtaining console text is quite difficult.

We could add a fixed delay there, but I'd like to avoid waiting that
long on every boot.  Why don't you add a kernel module_param named
something like ps3fb_delay that takes a value in milliseconds and a
default of zero.  See:

  https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/video/fbdev/ps3fb.c?h=v4.17#n260

> I suppose the problem is that it relies on interrupts for ps3fb_sync_image
> to regularly copy the image, hence without them the screen isn't updated to
> show kernel panics, etc. Perhaps one way to fix that is to implement the
> struct fb_tile_ops API, so that the console is synchronously updated? Would
> that be acceptable?

I'm not sure if that would work or not.   Maybe Geert is more familiar with it.

-Geoff