Hello Justin, Friday, June 08, 2001, 2:22:51 AM, you wrote: JS> Eugene Kuznetsov wrote: >> >> Next question is, why mmap() is failing? I tried to add a couple >> >> of printk()'s to find out what happens, and this looks quite weird >> >> for me. One of the first sanity checks in bttv_mmap() ( sources of >> >> 0.8.16 ) fails. It is: >> >> >> >> if (!(vma->vm_flags & VM_SHARED)) >> >> return -EINVAL; >> >> >> >> But, if I correctly understood what happens during the mmap() syscall >> >> ( /usr/src/linux/mm/mmap.c ), VM_SHARED flag is not set for mapping >> >> areas read-only! I tried to change protection in parameters to >> >> mmap(), but only to receive 'permission denied' instead of 'invalid >> >> argument', even as root. >> >> JS> Umm.. Try the attached patch - this may work... >> >> As I already mentioned, applying this change does not help, because >> then I receive 'permission denied'. JS> Now that is strange... The patched mmap command is now identical to that JS> used in xawtv! Has anybody else gotten this to work with bttv 0.8.16? JS> If so, please let us know how! This problem was really simple - you can't mmap() read-write when the device is opened read-only. After I fixed that, I even managed to capture something. I'll give more details tomorrow. -- Best regards, Eugene NetZero Platinum No Banner Ads and Unlimited Access Sign Up Today - Only $9.95 per month! http://www.netzero.net
