Re: [PATCH] fix for BZ 8426 - massive slowdown on SCSI CD/DVD drive connected to mptspi driver

[Doug Chapman <doug.chapman@hp.com>]

Eric,

Any feedback on this?  From looking at the code I am pretty sure I have
only restored things to the order where they were before the cleanup
patch but you obviously know the code better than I possibly could.

As this is a regression I would like to get this resolved before long.

thanks,

- Doug

On Mon, 2007-05-07 at 15:59 -0400, Doug Chapman wrote:
> Patch for: http://bugzilla.kernel.org/show_bug.cgi?id=8426
> 
> A recent code cleanup that moved code from mptscsih to mptspi
> inadvertently change the order some code was called.  This caused
> a massive slowdown (of 150x to 300x) on the CD/DVD drive on the
> high-end HP Integrity servers.
> 
> Signed-off-by: Doug Chapman <doug.chapman@hp.com>
> 
> 
> 
> 
> diff --git a/drivers/message/fusion/mptspi.c b/drivers/message/fusion/mptspi.c
> index 85f21b5..2eb5741 100644
> --- a/drivers/message/fusion/mptspi.c
> +++ b/drivers/message/fusion/mptspi.c
> @@ -726,13 +726,15 @@ static int mptspi_slave_configure(struct scsi_device *sdev)
>  	struct _MPT_SCSI_HOST *hd =
>  		(struct _MPT_SCSI_HOST *)sdev->host->hostdata;
>  	VirtTarget *vtarget = scsi_target(sdev)->hostdata;
> -	int ret = mptscsih_slave_configure(sdev);
> +	int ret;
> +
> +	mptspi_initTarget(hd, vtarget, sdev);
> +
> +	ret = mptscsih_slave_configure(sdev);
>  
>  	if (ret)
>  		return ret;
>  
> -	mptspi_initTarget(hd, vtarget, sdev);
> -
>  	ddvprintk((MYIOC_s_INFO_FMT "id=%d min_period=0x%02x"
>  		" max_offset=0x%02x max_width=%d\n", hd->ioc->name,
>  		sdev->id, spi_min_period(scsi_target(sdev)),
> 
>