[ltp] T43: No DMA for /dev/hdc (Ultrabay Slim HDD)

Felix E. Klee linux-thinkpad@linux-thinkpad.org
Fri, 08 Dec 2006 09:35:11 +0100


I inserted an Ultrabay Slim PATA HDD into a T43 when it was turned off.
Afterwards, I turned it on and booted into LINUX.  The drive is
accessible just fine.  However, it's awfully slow.  As it looks, the
reason is that DMA is not turned on, and trying to turn it on fails:

  ~# hdparm -d /dev/hdc

  /dev/hdc:
   using_dma    =  0 (off)
  ~# hdparm -d1 /dev/hdc

  /dev/hdc:
   setting using_dma to 1 (on)
   HDIO_SET_DMA failed: Operation not permitted
   using_dma    =  0 (off)

What can I do?

Further details:

* The drive works fine in a T41.

* I do *not* need support for hot swapping (which according to ThinkWiki
  is a problem with the T43).
-- 
Felix E. Klee