• Paulo Zanoni's avatar
    drm/i915: actually drive the BDW reserved IDs · 24fdd3f9
    Paulo Zanoni authored
    [ Upstream commit 98b2f01c ]
    
    Back in 2014, commit fb7023e0 ("drm/i915: BDW: Adding Reserved PCI
    IDs.") added the reserved PCI IDs in order to try to make sure we had
    working drivers in case we ever released products using these IDs
    (since we had instances of this type of problem in the past). The
    problem is that the patch only touched the macros used by
    early-quirks.c and by the user space components that rely on
    i915_pciids.h, it didn't touch the macros used by i915_pci.c. So we
    correctly handled the stolen memory for these theoretical IDs, but we
    didn't actually drive the devices from i915.ko.
    
    So this patch fixes the original commit by actually making i915.ko
    drive these IDs, which was the goal. There's no information on what
    would be the GT count on these IDs, so we just go with the safer
    intel_broadwell_info, at the risk of ignoring a possibly inexistent
    BSD2_RING.
    
    I did some checking, and it seems that these IDs are driven by
    intel-gpu-tools, xf86-video-intel and libdrm (since they contain old
    copies of i915_pciids.h), but they are not checked by mesa.
    
    The alternative to this patch would be to just assume we're actually
    never going to use these IDs, and then remove them from our ID lists
    and make sure our user space components sync the latest i915_pciids.h
    copy. I'm fine with either approaches, as long as we make sure that
    every component tries to drive the same list of PCI IDs.
    
    Fixes: fb7023e0 ("drm/i915: BDW: Adding Reserved PCI IDs.")
    Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
    Cc: Ben Widawsky <ben@bwidawsk.net>
    Cc: Jani Nikula <jani.nikula@intel.com>
    Signed-off-by: default avatarPaulo Zanoni <paulo.r.zanoni@intel.com>
    Reviewed-by: default avatarRodrigo Vivi <rodrigo.vivi@intel.com>
    Link: http://patchwork.freedesktop.org/patch/msgid/1483473860-17644-3-git-send-email-paulo.r.zanoni@intel.comSigned-off-by: default avatarSasha Levin <alexander.levin@verizon.com>
    Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    24fdd3f9
i915_pci.c 13.6 KB