From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757735AbcEEQNw (ORCPT ); Thu, 5 May 2016 12:13:52 -0400 Received: from foss.arm.com ([217.140.101.70]:50641 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756734AbcEEQNu (ORCPT ); Thu, 5 May 2016 12:13:50 -0400 From: Robin Murphy To: airlied@linux.ie, liviu.dudau@arm.com, dri-devel@lists.freedesktop.org Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH 2/2] drm: hdlcd: Suspend/resume only active crtcs Date: Thu, 5 May 2016 17:13:38 +0100 Message-Id: <759fe8d3dde95091a9df83018051cba00f494e1e.1462464611.git.robin.murphy@arm.com> X-Mailer: git-send-email 2.8.1.dirty In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The current PM ops simply unconditionally enable/disable the HDLCD, which proves problematic when there is no display plugged in - since without a crtc the hardware itself is still in an uninitialised state, coming out of suspend results in it being enabled without a valid framebuffer address, which typically results in it trying to scan out from bus address 0 and flooding the system with error interrupts. Fix this by checking the crtc state on resume, and only enabling the hardware if it's actually supposed to be. For the sake of consistency, do the same on the suspend path as well, although there it's merely a case of skipping unnecessary work. CC: Liviu Dudau Signed-off-by: Robin Murphy --- drivers/gpu/drm/arm/hdlcd_crtc.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/arm/hdlcd_crtc.c b/drivers/gpu/drm/arm/hdlcd_crtc.c index fef1b04c2aab..bf6ff5e48adc 100644 --- a/drivers/gpu/drm/arm/hdlcd_crtc.c +++ b/drivers/gpu/drm/arm/hdlcd_crtc.c @@ -296,12 +296,14 @@ static struct drm_plane *hdlcd_plane_init(struct drm_device *drm) void hdlcd_crtc_suspend(struct drm_crtc *crtc) { - hdlcd_crtc_disable(crtc); + if (crtc->state->active) + hdlcd_crtc_disable(crtc); } void hdlcd_crtc_resume(struct drm_crtc *crtc) { - hdlcd_crtc_enable(crtc); + if (crtc->state->active) + hdlcd_crtc_enable(crtc); } int hdlcd_setup_crtc(struct drm_device *drm) -- 2.8.1.dirty