From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9F43BC4167E for ; Mon, 25 Oct 2021 19:56:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8612A604E9 for ; Mon, 25 Oct 2021 19:56:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238780AbhJYT7H (ORCPT ); Mon, 25 Oct 2021 15:59:07 -0400 Received: from mail.kernel.org ([198.145.29.99]:42722 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235497AbhJYTzI (ORCPT ); Mon, 25 Oct 2021 15:55:08 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 08F2F610A6; Mon, 25 Oct 2021 19:45:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1635191132; bh=IIrpcUVTztwdklgZWMopXjqbhWQ1Nlwy6rmpCXx5ZZE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=iEI5zUtpi4zMjUMyiDF/2vg7yUgyS/frFPjFqJx7+IjLJfbPvIU05ZwT5MPwTpTpX 33TR2Hzus+Oaus/6CWNQDt221amW/S4/y7nATRk8kK4/8x0o9lk3RY/6GNvGWsev6y NCTtFKier2IPf3tdXPXvEyUvNOfH8wSW6PSd8+jA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Marek Vasut , Daniel Abrecht , Emil Velikov , Laurent Pinchart , Sam Ravnborg , Stefan Agner , Maarten Lankhorst Subject: [PATCH 5.14 122/169] drm: mxsfb: Fix NULL pointer dereference crash on unload Date: Mon, 25 Oct 2021 21:15:03 +0200 Message-Id: <20211025191033.309049783@linuxfoundation.org> X-Mailer: git-send-email 2.33.1 In-Reply-To: <20211025191017.756020307@linuxfoundation.org> References: <20211025191017.756020307@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Marek Vasut 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 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 Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/mxsfb/mxsfb_drv.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) --- 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 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); }