Re: [PATCH v2 2/6] scsi: libsas: Add sas_ata_device_link_abort()

[Damien Le Moal <damien.lemoal@opensource.wdc.com>]

On 2022/08/17 7:52, John Garry wrote:
> Similar to how AHCI handles NCQ errors in ahci_error_intr() ->
> ata_port_abort() -> ata_do_link_abort(), add an NCQ error handler for LLDDs
> to call to initiate a link abort.
> 
> This will mark all outstanding QCs as failed and kick-off EH.
> 
> Note:
> The ATA_EH_RESET flag is set for following reasons:
> - For hisi_sas, SATA device resources during error handling will only be
>   released during reset for ATA EH.
>   ATA EH could decide during autopsy that EH would not be required, so
>   ensure that it happens (by setting the flag).
> - Similar to hisi_sas, pm8001 NCQ error handling requires a hardreset to
>   ensure necessary recovery commands are sent (so again we require flag
>   ATA_EH_RESET to be set as an insurance policy).
> 
> Suggested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
> Signed-off-by: John Garry <john.garry@huawei.com>
> ---
>  drivers/scsi/libsas/sas_ata.c | 11 +++++++++++
>  include/scsi/sas_ata.h        |  5 +++++
>  2 files changed, 16 insertions(+)
> 
> diff --git a/drivers/scsi/libsas/sas_ata.c b/drivers/scsi/libsas/sas_ata.c
> index d35c9296f738..9daae64be37e 100644
> --- a/drivers/scsi/libsas/sas_ata.c
> +++ b/drivers/scsi/libsas/sas_ata.c
> @@ -861,6 +861,17 @@ void sas_ata_wait_eh(struct domain_device *dev)
>  	ata_port_wait_eh(ap);
>  }
>  
> +void sas_ata_device_link_abort(struct domain_device *device)
> +{
> +	struct ata_port *ap = device->sata_dev.ap;
> +	struct ata_link *link = &ap->link;
> +
> +	link->eh_info.err_mask |= AC_ERR_DEV;
> +	link->eh_info.action |= ATA_EH_RESET;

I am still not convinced that we should set this here. ata_eh_link_autopsy() and
ata_eh_analyze_serror() are supposed to set the action based on the error. Can't
you reuse the link autopsy function ?

> +	ata_link_abort(link);
> +}
> +EXPORT_SYMBOL_GPL(sas_ata_device_link_abort);
> +
>  int sas_execute_ata_cmd(struct domain_device *device, u8 *fis, int force_phy_id)
>  {
>  	struct sas_tmf_task tmf_task = {};
> diff --git a/include/scsi/sas_ata.h b/include/scsi/sas_ata.h
> index a1df4f9d57a3..cad0b33064a5 100644
> --- a/include/scsi/sas_ata.h
> +++ b/include/scsi/sas_ata.h
> @@ -32,6 +32,7 @@ void sas_probe_sata(struct asd_sas_port *port);
>  void sas_suspend_sata(struct asd_sas_port *port);
>  void sas_resume_sata(struct asd_sas_port *port);
>  void sas_ata_end_eh(struct ata_port *ap);
> +void sas_ata_device_link_abort(struct domain_device *dev);
>  int sas_execute_ata_cmd(struct domain_device *device, u8 *fis,
>  			int force_phy_id);
>  int sas_ata_wait_after_reset(struct domain_device *dev, unsigned long deadline);
> @@ -87,6 +88,10 @@ static inline void sas_ata_end_eh(struct ata_port *ap)
>  {
>  }
>  
> +static inline void sas_ata_device_link_abort(struct domain_device *dev)
> +{
> +}
> +
>  static inline int sas_execute_ata_cmd(struct domain_device *device, u8 *fis,
>  				      int force_phy_id)
>  {


-- 
Damien Le Moal
Western Digital Research