On Wed, Jan 15, 2014 at 11:45 PM, m silverstri < [email protected]> wrote:
> Hi, > > If my application allocate memory for input and output buffers, and > pass the pointer to a kernel driver (via v4l2 queue buffer operation), > can the kernel driver access it? Do I need to setup DMA before teh > kernel driver can read/write to it? > You can transfer data to & from kernelspace/userspace by using copy_to/from_user() API. However, for DMA I think you might also want to lock the user pages in memory so that they are not invalidated when the owning process is scheduled out. This is a very high-level gist, but there a lot of resources out there which show how this can be done. HTH, -mandeep > > Thank you. > > _______________________________________________ > Kernelnewbies mailing list > [email protected] > http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies >
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