[PATCH][v3] driver/FSL SATA:Fix wrong Device Error Register usage

[Kushwaha Prabhakar-B32579]

Hi Jeff,

I am not finding any new comments on this.

Could you please ACK this patch so that it can be applied on external list. 

--Prabhakar


> -----Original Message-----
> From: Kushwaha Prabhakar-B32579
> Sent: Wednesday, March 09, 2011 12:47 PM
> To: linux-ide at vger.kernel.org
> Cc: linuxppc-dev at lists.ozlabs.org; jgarzik at pobox.com;
> meet2prabhu at gmail.com; Kushwaha Prabhakar-B32579; Kalra Ashish-B00888
> Subject: [PATCH][v3] driver/FSL SATA:Fix wrong Device Error Register
> usage
> 
> When a single device error is detected, the device under the error is
> indicated by the error bit set in the DER. There is a one to one mapping
> between register bit and devices on Port multiplier(PMP) i.e. bit 0
> represents PMP device 0 and bit 1 represents PMP device 1 etc.
> 
> Current implementation treats Device error register value as device
> number not set of bits representing multiple device on PMP. It is changed
> to consider bit level.
> No need to check for each set bit as all command is going to be aborted.
> 
> Signed-off-by: Ashish Kalra <B00888 at freescale.com>
> Signed-off-by: Prabhakar Kushwaha <prabhakar at freescale.com>
> ---
> 
>  git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
> (branch master)
> 
>  This patch is already gone through review of linuxppc-dev mail list.
>  Making CC linuxppc-dev at lists.ozlabs.org
> 
>  Changes for v2: Incorporated Sergei Shtylyov's comment
> 	- Put space after -
> 	- added a line
>  Changes for v3: Incorporated David Laight's comment
>  	- Condition check for dereg 0 for hardware error
> 
>  drivers/ata/sata_fsl.c |    7 +++++--
>  1 files changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/ata/sata_fsl.c b/drivers/ata/sata_fsl.c index
> b0214d0..ad84ddc 100644
> --- a/drivers/ata/sata_fsl.c
> +++ b/drivers/ata/sata_fsl.c
> @@ -1040,12 +1040,15 @@ static void sata_fsl_error_intr(struct ata_port
> *ap)
> 
>  		/* find out the offending link and qc */
>  		if (ap->nr_pmp_links) {
> +			unsigned int dev_num;
> +
>  			dereg = ioread32(hcr_base + DE);
>  			iowrite32(dereg, hcr_base + DE);
>  			iowrite32(cereg, hcr_base + CE);
> 
> -			if (dereg < ap->nr_pmp_links) {
> -				link = &ap->pmp_link[dereg];
> +			dev_num = ffs(dereg) - 1;
> +			if (dev_num < ap->nr_pmp_links && dereg != 0) {
> +				link = &ap->pmp_link[dev_num];
>  				ehi = &link->eh_info;
>  				qc = ata_qc_from_tag(ap, link->active_tag);
>  				/*
> --
> 1.7.3