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@denx.de Cc: Daniel Abrecht public@danielabrecht.ch Cc: Emil Velikov emil.l.velikov@gmail.com Cc: Laurent Pinchart laurent.pinchart@ideasonboard.com Cc: Sam Ravnborg sam@ravnborg.org Cc: Stefan Agner stefan@agner.ch --- drivers/gpu/drm/mxsfb/mxsfb_drv.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/mxsfb/mxsfb_drv.c b/drivers/gpu/drm/mxsfb/mxsfb_drv.c index ec0432fe1bdf..86d78634a979 100644 --- a/drivers/gpu/drm/mxsfb/mxsfb_drv.c +++ b/drivers/gpu/drm/mxsfb/mxsfb_drv.c @@ -173,7 +173,11 @@ static void mxsfb_irq_disable(struct drm_device *drm) struct mxsfb_drm_private *mxsfb = drm->dev_private;

mxsfb_enable_axi_clk(mxsfb); - mxsfb->crtc.funcs->disable_vblank(&mxsfb->crtc); + + /* Disable and clear VBLANK IRQ */ + writel(CTRL1_CUR_FRAME_DONE_IRQ_EN, mxsfb->base + LCDC_CTRL1 + REG_CLR); + writel(CTRL1_CUR_FRAME_DONE_IRQ, mxsfb->base + LCDC_CTRL1 + REG_CLR); + mxsfb_disable_axi_clk(mxsfb); }