• Ben Skeggs's avatar
    drm/nouveau/fbcon: using nv_two_heads is not a good idea · 9bd0c15f
    Ben Skeggs authored
    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: default avatarBen Skeggs <bskeggs@redhat.com>
    Cc: stable@vger.kernel.org
    Signed-off-by: default avatarDave Airlie <airlied@redhat.com>
    9bd0c15f
nouveau_fbcon.c 13.8 KB