Re: [PATCH] pata_cmd64x: Set up MWDMA modes properly

[Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>]

On Saturday 11 August 2007, Sergei Shtylyov wrote:
> Hello.
> 
> Alan Cox wrote:
> 
> > Set the MWDMA timing by updating the correct registers. Split the PIO
> > path as this is mostly shared code. Wants testing.
> 
>     Cool! So much simpler than my fix to the old IDE driver...
> 
> > Signed-off-by: Alan Cox <alan@redhat.com>
> 
> Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
> 
> > diff -u --new-file --recursive --exclude-from /usr/src/exclude linux.vanilla-2.6.23rc1-mm1/drivers/ata/pata_cmd64x.c linux-2.6.23rc1-mm1/drivers/ata/pata_cmd64x.c
> > --- linux.vanilla-2.6.23rc1-mm1/drivers/ata/pata_cmd64x.c	2007-07-26 15:01:52.000000000 +0100
> > +++ linux-2.6.23rc1-mm1/drivers/ata/pata_cmd64x.c	2007-08-08 11:52:23.000000000 +0100
> [...]
> > @@ -117,8 +118,9 @@
> >  	int arttim = arttim_port[ap->port_no][adev->devno];
> >  	int drwtim = drwtim_port[ap->port_no][adev->devno];
> >  
> > -
> > -	if (ata_timing_compute(adev, adev->pio_mode, &t, T, 0) < 0) {
> > +	/* ata_timing_compute is smart and will produce timings for MWDMA
> > +	   that don't violate the drives PIO capabilities. */
> > +	if (ata_timing_compute(adev, mode, &t, T, 0) < 0) {
> >  		printk(KERN_ERR DRV_NAME ": mode computation failed.\n");
> >  		return;
> >  	}
> 
>     That function rocks (except I didn't get what the address setup timings 
> mean to SW/MW DMA)...

JFYI: this function was "borrowed" from drivers/ide/ide-timing.h,
you can use it in IDE host drivers as well... ;)

Bart