Re: [PATCH 1/6] scsi: hisi_sas: workaround STP link SoC bug

[Johannes Thumshirn]

On Mon, Apr 10, 2017 at 09:21:56PM +0800, John Garry wrote:
> From: Xiaofei Tan <tanxiaofei@xxxxxxxxxx>
> 
> After resetting the controller, the process of scanning SATA disks
> attached to an expander may fail occasionally. The issue is that
> the controller can't close the STP link created by target if the
> max link time is 0.
> 
> To workaround this issue, we reject STP link after resetting the
> controller, and change the corresponding PHY to accept STP link
> only after receiving data.
> 
> We do this check in cq interrupt handler. In order not to reduce
> efficiency, we use an variable to control whether we should check
> and change PHY to accept STP link.
> 
> The function phys_reject_stp_links_v2_hw() should be called after
> resetting the controller.
> 
> The solution of another SoC bug "SATA IO timeout", that also uses
> the same register to control STP link, is not effective before
> the PHY accepts STP link.
> 
> Signed-off-by: Xiaofei Tan <tanxiaofei@xxxxxxxxxx>
> Signed-off-by: John Garry <john.garry@xxxxxxxxxx>
> ---

Looks good,
Reviewed-by: Johannes Thumshirn <jthumshirn@xxxxxxx>

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Johannes Thumshirn                                          Storage
jthumshirn@xxxxxxx                                +49 911 74053 689
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