From: Marek Vasut Date: Sat, 16 Oct 2021 21:04:46 +0000 (+0200) Subject: drm: mxsfb: Fix NULL pointer dereference crash on unload X-Git-Tag: accepted/tizen/unified/20230118.172025~6114^2~3^2~10 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=3cfc183052c3dbf8eae57b6c1685dab00ed3db4a;p=platform%2Fkernel%2Flinux-rpi.git drm: mxsfb: Fix NULL pointer dereference crash on unload 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 Cc: Daniel Abrecht Cc: Emil Velikov Cc: Laurent Pinchart Cc: Sam Ravnborg Cc: Stefan Agner Signed-off-by: Sam Ravnborg Link: https://patchwork.freedesktop.org/patch/msgid/20211016210446.171616-1-marex@denx.de Signed-off-by: Maarten Lankhorst --- diff --git a/drivers/gpu/drm/mxsfb/mxsfb_drv.c b/drivers/gpu/drm/mxsfb/mxsfb_drv.c index ec0432f..86d7863 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); }