From: Marek Vasut <marex@denx.de> stable inclusion from stable-5.10.76 commit f40c2281d2c0674d32ba732fee45222d76495472 bugzilla: 182988 https://gitee.com/openeuler/kernel/issues/I4IAHF Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- commit 3cfc183052c3dbf8eae57b6c1685dab00ed3db4a upstream. 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> Signed-off-by: Sam Ravnborg <sam@ravnborg.org> Link: https://patchwork.freedesktop.org/patch/msgid/20211016210446.171616-1-marex@... Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Chen Jun <chenjun102@huawei.com> Acked-by: Weilong Chen <chenweilong@huawei.com> Signed-off-by: Chen Jun <chenjun102@huawei.com> --- 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 f31e8ef3c258..25e422d2e7f8 100644 --- a/drivers/gpu/drm/mxsfb/mxsfb_drv.c +++ b/drivers/gpu/drm/mxsfb/mxsfb_drv.c @@ -268,7 +268,11 @@ 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); } -- 2.20.1