From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932604Ab2GASQy (ORCPT ); Sun, 1 Jul 2012 14:16:54 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:47079 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932576Ab2GASQw (ORCPT ); Sun, 1 Jul 2012 14:16:52 -0400 Message-Id: <20120701172009.653307435@decadent.org.uk> User-Agent: quilt/0.60-1 Date: Sun, 01 Jul 2012 18:20:27 +0100 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Ben Skeggs , Dave Airlie Subject: [ 21/48] drm/nouveau/fbcon: using nv_two_heads is not a good idea In-Reply-To: <20120701172006.535271340@decadent.org.uk> X-SA-Exim-Connect-IP: 2001:470:1f08:1539:21c:bfff:fe03:f805 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ben Skeggs commit 9bd0c15fcfb42f6245447c53347d65ad9e72080b upstream. nv_two_heads() was never meant to be used outside of pre-nv50 code. The code checks for >= NV_10 for 2 CRTCs, then downgrades a few specific chipsets to 1 CRTC based on (pci_device & 0x0ff0). The breakage example seen is on GTX 560Ti, with a pciid of 0x1200, which gets detected as an NV20 (0x020x) with 1 CRTC by nv_two_heads(), causing memory corruption because there's actually 2 CRTCs.. This switches fbcon to use the CRTC count directly from the mode_config structure, which will also fix the same issue on Kepler boards which have 4 CRTCs. Signed-off-by: Ben Skeggs Signed-off-by: Dave Airlie Signed-off-by: Ben Hutchings --- drivers/gpu/drm/nouveau/nouveau_fbcon.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/nouveau/nouveau_fbcon.c b/drivers/gpu/drm/nouveau/nouveau_fbcon.c index 153b9a1..1074bc5 100644 --- a/drivers/gpu/drm/nouveau/nouveau_fbcon.c +++ b/drivers/gpu/drm/nouveau/nouveau_fbcon.c @@ -467,7 +467,7 @@ int nouveau_fbcon_init(struct drm_device *dev) nfbdev->helper.funcs = &nouveau_fbcon_helper_funcs; ret = drm_fb_helper_init(dev, &nfbdev->helper, - nv_two_heads(dev) ? 2 : 1, 4); + dev->mode_config.num_crtc, 4); if (ret) { kfree(nfbdev); return ret;