From mboxrd@z Thu Jan 1 00:00:00 1970 From: Konrad Rzeszutek Wilk Subject: Re: i915 KMS framebuffer issues in 4.2.1/3.7.1. Date: Fri, 4 Jan 2013 16:36:39 -0500 Message-ID: <20130104213639.GA8308@phenom.dumpdata.com> References: <201212261439.qBQEdOFl017226@wind.enjellic.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <201212261439.qBQEdOFl017226@wind.enjellic.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: greg@enjellic.com Cc: xen-devel@lists.xen.org List-Id: xen-devel@lists.xenproject.org On Wed, Dec 26, 2012 at 08:39:24AM -0600, Dr. Greg Wettstein wrote: > Good morning, hope the week is going well for everyone. > > We have been putting 4.2.1 through its paces and noted an issue which > is specific to the kernel running on top of the hypervisor. It isn't > specific to 4.2.1 but we validated the issue on this platform and on > the 3.7.1 kernel for completeness. > > An attempt to mmap the framebuffer provided by the i915 KMS driver > causes a fork() to fail with ENOMEM. Same hardware and kernel on Is the kernel compiled with CONFIG_INTEL_DMAR .. something? > bare-metal works fine. The 'fbterm' utility demonstrates the problem > but we can demonstrate on a minimal implemenation of 'mmap + forkpty'. It could be that the _PAGE_IOMAP flag needs to be set. There was a patch floating around for that. Hmm, could be this: http://git.kernel.org/?p=linux/kernel/git/konrad/xen.git;a=commit;h=0cfd8ac8e702db147a9a664212f597f627b3f7e9 or these two patches: http://git.kernel.org/?p=linux/kernel/git/konrad/xen.git;a=shortlog;h=refs/heads/devel/ioperm but not sure. > > Would be happy to test any patches or ideas if people have a though on > the issue. > > Have a good day. > > As always, > Dr. G.W. Wettstein, Ph.D. Enjellic Systems Development, LLC. > 4206 N. 19th Ave. Specializing in information infra-structure > Fargo, ND 58102 development. > PH: 701-281-1686 > FAX: 701-281-3949 EMAIL: greg@enjellic.com > ------------------------------------------------------------------------------ > "Experience is something you don't get until just after you need it." > -- Olivier > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xen.org > http://lists.xen.org/xen-devel >