Date: Mon, 9 Oct 2006 17:43:29 -0700 From: John-Mark Gurney <gurney_j@resnet.uoregon.edu> To: Jonathan Chen <jon@freebsd.org> Cc: freebsd-hackers@freebsd.org Subject: Re: bktr(4) risk? Message-ID: <20061010004329.GU793@funkthat.com> In-Reply-To: <20061009233903.GB20969@porthos.spock.org> References: <20061009213733.GC15088@porthos.spock.org> <20061009232649.GT793@funkthat.com> <20061009233903.GB20969@porthos.spock.org>
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Jonathan Chen wrote this message on Mon, Oct 09, 2006 at 19:39 -0400: > On Mon, Oct 09, 2006 at 04:26:50PM -0700, John-Mark Gurney wrote: > > Jonathan Chen wrote this message on Mon, Oct 09, 2006 at 17:37 -0400: > > > doesn't seem too useful a task for a video capture card to be doing. > > > Perhaps we should put a test for write access in there or just eliminate > > > the ioctl altogether. It should be noted that the meteor driver had this > > > ioctl ifdef'ed out prior to its removal. > > > > Hmmm... I think I'll go ahead and put in a compatibility ioctl based > > on the way I did the zoran driver, and schedule the removal of the > > ioctl.. > > Zoran driver? Can I have a pointer or a summary of what you did there so I > can do the same to meteor(4)? http://people.freebsd.org/~jmg/zoran.html There is a function verify_contig in zr_os.c, but we should teach meteor(4) and friends how to use bus_dma to do the buffer now that I think about it... The work that I do to verify that the buffer is contiguous should be done by bus_dma... We should make the user process mmap the video buffer, and then pass the user's address to the driver... Using a properly crafted uio struct, you can use bus_dmamap_load_uio to get the correct physical address of the buffer to program the card with... You can create a tag w/ only 1 segment to ensure that the mapping will be contigious... -- John-Mark Gurney Voice: +1 415 225 5579 "All that I will do, has been done, All that I have, has not."
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