Date: Thu, 17 Dec 2009 09:37:39 -0500 From: "Greg Rowe" <greg@rowes.org> To: "'Robert Noland'" <rnoland@FreeBSD.org> Cc: freebsd-x11@FreeBSD.org Subject: RE: Radeon HD4850 DRI Issues Message-ID: <6D9629ACBA89464799BD1DD1C50CBA10@GregPC> In-Reply-To: <1261004962.26065.29.camel@balrog.2hip.net> References: <200912071550.56061.greg@rowes.org> <1261004962.26065.29.camel@balrog.2hip.net>
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Thanks Robert, My system is available for any testing you may need as you work on a fix. I can wipe it and get to any software level you need. Greg > Ok, I've found the issue now... It is a somewhat invasive solution > though, so it will take me a little time. > > Basically, the issue is this. We create a list of maps either in the > kernel or via userland requesting them to be added. Each map has an > offset associated with it for mmap. Mostly the offsets are all kernel > virtual addresses, but a few (register and framebuffer maps) are > physical addresses. On i386, when we allocate scatter gather memory for > the GART aperture (32Mb on radeon) it is being allocated at the end of > the kva space. I have gone back and looked at all of the reports of > this that I have and the framebuffer is always at 0xe0000000. When the > kva returned by bus_dma overlaps with the physical address of the > framebuffer, we match the incorrect map when mmap is called and > therefore we are actually mapping the ring buffer inside of the > framebuffer, rather that out of the scatter gather memory where it > belongs. > > I have never seen this issue on amd64. On i386 when the framebuffer is > located lower than 0xe0000000 things mostly work as well. I have to > overhaul the way that we handle mmap offsets to get this sorted out and > possibly make a couple of changes to libdrm, which is shared code. > > robert. > > > Thanks, > > Greg > > > > _______________________________________________ > > freebsd-x11@freebsd.org mailing list > > http://lists.freebsd.org/mailman/listinfo/freebsd-x11 > > To unsubscribe, send any mail to "freebsd-x11-unsubscribe@freebsd.org" > -- > Robert Noland <rnoland@FreeBSD.org> > FreeBSD >
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