Re: usb_bulk_msg timeout w/ rvmalloc

[Pete Zaitcev <zaitcev@redhat.com>]

>      I have written a driver which, in part, facilitates the usb bulk 
>      transfer of raw image data. It works fine for small (CIF, QCIF) 
>      images, but for larger images, kmalloc will not allocate enough 
>      memory. 

How much do you need?
     
>      I copied the rvmalloc code from the cpia2 driver and used it in place 
>      of kmalloc. The memory allocates fine, but usb_bulk_msg now times out 
>      when using the pointer to the rvmalloc'd memory. I have been unable to 
>      find an instance of an existing driver using rvmalloc in conjunction 
>      with usb_bulk_msg. 

The best thing would be to use pipelined transfer with
several URBs, I think. If that is too difficult for you,
try to use __get_free_pages(), but mind that even if free
RAM is available, kernel may not be able to fulfill your
request. Check response codes carefuly.

-- Pete