Re: [PATCH #upstream-fixes] pata_cmd64x: revert commit d62f5576

[Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>]

On Tuesday 17 August 2010 02:13:42 pm Tejun Heo wrote:
> Commit d62f5576 (pata_cmd64x: fix handling of address setup timings)
> incorrectly called ata_timing_compute() on UDMA mode on 0 @UT leading
> to devide by zero fault.  Revert it until better fix is available.
> This is reported in bko#16607 by Milan Kocian who also root caused it.
> 
>   https://bugzilla.kernel.org/show_bug.cgi?id=16607

How's about giving the ATA maintainer some time to resolve the issue
properly?

The revert should be a last resort action (+ the issue was reported
only yesterday) as it introduces another regression (it just replaces
new bug with the old bug while adding noise in the process)..

> Signed-off-by: Tejun Heo <tj@kernel.org>
> Reported-and-root-caused-by: Milan Kocian <milan.kocian@wq.cz>
> Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
> Cc: stable@kernel.org
> ---
>  drivers/ata/pata_cmd64x.c |    6 ------
>  1 file changed, 6 deletions(-)
> 
> diff --git a/drivers/ata/pata_cmd64x.c b/drivers/ata/pata_cmd64x.c
> index 9f5da1c..905ff76 100644
> --- a/drivers/ata/pata_cmd64x.c
> +++ b/drivers/ata/pata_cmd64x.c
> @@ -121,14 +121,8 @@ static void cmd64x_set_timing(struct ata_port *ap, struct ata_device *adev, u8 m
> 
>  		if (pair) {
>  			struct ata_timing tp;
> -
>  			ata_timing_compute(pair, pair->pio_mode, &tp, T, 0);
>  			ata_timing_merge(&t, &tp, &t, ATA_TIMING_SETUP);
> -			if (pair->dma_mode) {
> -				ata_timing_compute(pair, pair->dma_mode,
> -						&tp, T, 0);
> -				ata_timing_merge(&tp, &t, &t, ATA_TIMING_SETUP);
> -			}
>  		}
>  	}