From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752244AbdHIXDK (ORCPT ); Wed, 9 Aug 2017 19:03:10 -0400 Received: from mail-pf0-f180.google.com ([209.85.192.180]:34661 "EHLO mail-pf0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752047AbdHIXDI (ORCPT ); Wed, 9 Aug 2017 19:03:08 -0400 From: Matthias Kaehlcke To: zijun_hu , Andrew Morton Cc: linux-kernel@vger.kernel.org, Doug Anderson , Nick Desaulniers , Greg Hackmann , Yury Norov , Ard Biesheuvel , Matthias Kaehlcke Subject: [PATCH v2] drm/rockchip: Skip suspend/resume if no display is attached Date: Wed, 9 Aug 2017 16:03:02 -0700 Message-Id: <20170809230302.107975-1-mka@chromium.org> X-Mailer: git-send-email 2.14.0.434.g98096fd7a8-goog Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org rockchip_drm_sys_suspend/resume() obains a struct drm_device pointer from drvdata, the pointer is then dereferenced to obtain private data. drvdata is set when a display is bound, on systems without a (successfully probed) display drvdata is NULL and the PM functions try to dereference a NULL pointer. The suspend/resume code relies on a valid drm_device object, skip it if the pointer is NULL. Signed-off-by: Matthias Kaehlcke --- drivers/gpu/drm/rockchip/rockchip_drm_drv.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_drv.c b/drivers/gpu/drm/rockchip/rockchip_drm_drv.c index c6b1b7f3a2a3..6228145d9496 100644 --- a/drivers/gpu/drm/rockchip/rockchip_drm_drv.c +++ b/drivers/gpu/drm/rockchip/rockchip_drm_drv.c @@ -275,11 +275,16 @@ static void rockchip_drm_fb_resume(struct drm_device *drm) static int rockchip_drm_sys_suspend(struct device *dev) { struct drm_device *drm = dev_get_drvdata(dev); - struct rockchip_drm_private *priv = drm->dev_private; + struct rockchip_drm_private *priv; + + if (!drm) + /* no display attached */ + return 0; drm_kms_helper_poll_disable(drm); rockchip_drm_fb_suspend(drm); + priv = drm->dev_private; priv->state = drm_atomic_helper_suspend(drm); if (IS_ERR(priv->state)) { rockchip_drm_fb_resume(drm); @@ -293,8 +298,13 @@ static int rockchip_drm_sys_suspend(struct device *dev) static int rockchip_drm_sys_resume(struct device *dev) { struct drm_device *drm = dev_get_drvdata(dev); - struct rockchip_drm_private *priv = drm->dev_private; + struct rockchip_drm_private *priv; + + if (!drm) + /* no display attached */ + return 0; + priv = drm->dev_private; drm_atomic_helper_resume(drm, priv->state); rockchip_drm_fb_resume(drm); drm_kms_helper_poll_enable(drm); -- 2.14.0.434.g98096fd7a8-goog