[PATCH] drm: mxsfb: Fix NULL pointer dereference crash on unload

[Sam Ravnborg]

Hi Marek,

On Sat, Oct 16, 2021 at 11:04:46PM +0200, Marek Vasut wrote:
> The mxsfb->crtc.funcs may already be NULL when unloading the driver,
> in which case calling mxsfb_irq_disable() via drm_irq_uninstall() from
> mxsfb_unload() leads to NULL pointer dereference.
> 
> Since all we care about is masking the IRQ and mxsfb->base is still
> valid, just use that to clear and mask the IRQ.
> 
> Fixes: ae1ed00932819 ("drm: mxsfb: Stop using DRM simple display pipeline helper")
> Signed-off-by: Marek Vasut <marex at denx.de>
> Cc: Daniel Abrecht <public at danielabrecht.ch>
> Cc: Emil Velikov <emil.l.velikov at gmail.com>
> Cc: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> Cc: Sam Ravnborg <sam at ravnborg.org>
> Cc: Stefan Agner <stefan at agner.ch>

Applied to drm-misc-fixes.

	Sam