On Sun, 6 Jan 2008 17:27:38 +0100 Bartlomiej Zolnierkiewicz wrote: > On Sunday 06 January 2008, FD Cami wrote: > > On Sun, 6 Jan 2008 13:36:09 +0000 > > Alan Cox wrote: > > > > > On Sun, 6 Jan 2008 08:03:31 +0300 > > > > > For now you can boot with libata.dma=1 to select DMA on disks > > > > > but not CD > > > > > > > > Great, but why isn't this in the documentation? > > > > > > Send patches > > > > patch attached. > > > > Description : Add libata.dma= to Documentation/kernel-parameters.txt > > > > Found documentation in : > > http://www.mail-archive.com/linux-ide%40vger.kernel.org/msg09849.html > > http://www.redhat.com/archives/fedora-extras-commits/2007-October/msg04568.html > > > > Signed-off-by: François Cami > > diff -rU2 linux-2.6.24-rc6/Documentation/kernel-parameters.txt > linux-2.6.24-rc6-mine/Documentation/kernel-parameters.txt > --- > linux-2.6.24-rc6/Documentation/kernel-parameters.txt        2008-01-06 > 15:58:54.000000000 +0100 +++ > linux-2.6.24-rc6-mine/Documentation/kernel-parameters.txt   2008-01-06 > 16:11:20.000000000 +0100 @@ -883,4 +883,11 @@ C2 power state. > +       libata.dma=     [LIBATA] DMA control > +                       libata.dma=0      Disable all PATA DMA like > old IDE > > this doesn't seem entirely correct: > > * IDE has "hdx=nodma" so you can disable DMA on per-device basis I think that libata.dma=1 is designed to behave like CONFIG_IDEDMA_ONLYDISK used to. "hdx=nodma" is more fine-grained than this. > * is this really limited to PATA? Alan's original patch took care of PATA. SATA support was added later by Jeff Garzik. Corrected documentation patch attached. > +                       libata.dma=1      Disk DMA only > +                       libata.dma=2      ATAPI DMA only > +                       libata.dma=3      CF DMA only This is also wrong, it should be "libata.dma=4      CF DMA only" Thanks to Zoltan Boszormenyi for catching this mistake. Revised patch attached. Best, François