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

[Sam Ravnborg]

Hi Marek,

On Wed, Sep 08, 2021 at 08:24:20PM +0200, Daniel Vetter wrote:
> On Tue, Sep 07, 2021 at 04:49:00AM +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>
> 
> You probably want a drm_atomic_helper_shutdown instead of trying to do all
> that manually. We've also added a bunch more devm and drmm_ functions to
> automate the cleanup a lot more here, e.g. your drm_mode_config_cleanup is
> in the wrong place.

I have applied v2 of this patch today - but failed to see any response
in v2 to this comment from Daniel. Was it lost somehow?

	Sam