From: Ben Skeggs Date: Tue, 26 Jun 2012 02:12:30 +0000 (+1000) Subject: drm/nouveau/fbcon: using nv_two_heads is not a good idea X-Git-Tag: firefly_0821_release~7541^2~995 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=46f82ddcd34cba5230ddbd914f8e18898ab55355;p=firefly-linux-kernel-4.4.55.git drm/nouveau/fbcon: using nv_two_heads is not a good idea 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: Greg Kroah-Hartman --- diff --git a/drivers/gpu/drm/nouveau/nouveau_fbcon.c b/drivers/gpu/drm/nouveau/nouveau_fbcon.c index 39aee6d4daf8..ea71f78fb552 100644 --- a/drivers/gpu/drm/nouveau/nouveau_fbcon.c +++ b/drivers/gpu/drm/nouveau/nouveau_fbcon.c @@ -487,7 +487,7 @@ 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;