Re: [PATCH #upstream] libata: clear eh_info on reset completion

[Zdenek Kaspar <zkaspar82@gmail.com>]

Tejun Heo napsal(a):
> Resets are done with port frozen but some controllers still issue
> interrupts during reset and they may end up recording error conditions
> in ehi leading to unnecessary EH retrials.
> 
> This patch makes ata_eh_reset() clear ehi on reset completion.  As
> reset is the most severe recovery action, there's nothing to lose by
> clearing ehi on its completion.
> 
> Signed-off-by: Tejun Heo <tj@kernel.org>
> Reported-by: Zdenek Kaspar <zkaspar82@gmail.com>
> ---
> Zdenek, I moved the clearing above a bit.  It should work the same but
> can you please test this one too?
> 
> Jeff, after Zdenek's verification, please commit this to #upstream.
> 
> Thanks.
> 
>  drivers/ata/libata-eh.c |   12 +++++++++---
>  1 file changed, 9 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
> index a3df9fe..924a8de 100644
> --- a/drivers/ata/libata-eh.c
> +++ b/drivers/ata/libata-eh.c
> @@ -2572,11 +2572,17 @@ int ata_eh_reset(struct ata_link *link, int classify,
>  			postreset(slave, classes);
>  	}
> 
> -	/* clear cached SError */
> +	/*
> +	 * Some controllers can't be frozen very well and may set
> +	 * spuruious error conditions during reset.  Clear accumulated
> +	 * error information.  As reset is the final recovery action,
> +	 * nothing is lost by doing this.
> +	 */
>  	spin_lock_irqsave(link->ap->lock, flags);
> -	link->eh_info.serror = 0;
> +	memset(&link->eh_info, 0, sizeof(link->eh_info));
>  	if (slave)
> -		slave->eh_info.serror = 0;
> +		memset(&slave->eh_info, 0, sizeof(link->eh_info));
> +	ap->pflags &= ~ATA_PFLAG_EH_PENDING;
>  	spin_unlock_irqrestore(link->ap->lock, flags);
> 
>  	/* Make sure onlineness and classification result correspond.

Successfully tested with ICH8 and ICH7R controllers on two different
machines with 2.6.31-rc3.

Z.