On Mon, Dec 15, 2014 at 7:48 PM, Dave Airlie airlied@gmail.com wrote:
On 16 December 2014 at 10:35, Linus Torvalds torvalds@linux-foundation.org wrote:
On Sun, Dec 14, 2014 at 11:17 PM, Dave Airlie airlied@linux.ie wrote:
i915: Initial Skylake (SKL) support gen3/4 reset work start of dri1/ums removal infoframe tracking fixes for lots of things.
So I'm not sure how happy I am about this. It seems to work, but on the very first boot I get this:
------------[ cut here ]------------ WARNING: CPU: 1 PID: 1292 at drivers/gpu/drm/i915/i915_gem_execbuffer.c:125 eb_lookup_vmas.isra.18+0x333/0x3d0 [i915]() GPU use of dumb buffer is illegal. Modules linked in: ip6t_rpfilter bnep ip6t_REJECT nf_reject_ipv6 bluetooth nf_conntrack_ipv6 ... video CPU: 1 PID: 1292 Comm: Xorg Not tainted 3.18.0-09423-g988adfdffdd4 #1 Hardware name: /DH87RL, BIOS RLH8710H.86A.0327.2014.0924.1645 09/24/2014 Call Trace: dump_stack+0x45/0x57 warn_slowpath_common+0x80/0xc0 warn_slowpath_fmt+0x41/0x50 ? sg_kfree+0x30/0x30 eb_lookup_vmas.isra.18+0x333/0x3d0 [i915] i915_gem_do_execbuffer.isra.25+0x50d/0xd80 [i915] ? unlock_page+0x6d/0x80 i915_gem_execbuffer2+0xb1/0x2c0 [i915] drm_ioctl+0x19c/0x630 [drm] do_vfs_ioctl+0x2e0/0x4e0 ? file_has_perm+0x87/0xa0 ? __audit_syscall_entry+0xac/0x100 SyS_ioctl+0x81/0xa0 ? do_page_fault+0xc/0x10 system_call_fastpath+0x12/0x17 ---[ end trace cb3c78163212ca1d ]---
apparently Introduced by commit 355a70183848 ("drm/gem: Warn on illegal use of the dumb buffer interface v2")
The commit says "the next step is to fail".
And I want to make it painfully clear that if somebody breaks existing working setups, they don't get to work on the kernel.
So get rid of the warning. And get rid of the notion that you can just fail. You can try to fix Xorg, and then come back to this - in a couple of years - when it no longer happens.
I'd be inclined to just revert this for now, it is annoying we let userspace away with this, but we probably need to find a better way to enforce it, since the cat is out of the bag.
Replace w/ DRM_ERROR? (perhaps ratelimited..)?
It's not a driver error, so much as a warning for userspace that it is doing something that is not expected to work on all hw / generations, and it appears to be finding more or less what it was intended to find, although I'm not sure the stack trace serves much purpose.
BR, -R
Dave. _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/dri-devel