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[SCSI] libsas: use libata-eh-reset for sata rediscovery fis transmit failures

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Since sata devices can take several seconds to recover the link on reset
the 0.5 seconds that libsas currently waits may not be enough.  Instead
if we are rediscovering a phy that was previously attached to a sata
device let libata handle any resets to encourage the device to transmit
the initial fis.

Once sas_ata_hard_reset() and lldds learn how to honor 'deadline' libsas
should stop encountering phys in an intermediate state, until then this
will loop until the fis is transmitted or ->attached_sas_addr gets
cleared, but in the more likely initial discovery case we keep existing
behavior.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
This commit is contained in:
Dan Williams 2011-11-30 23:23:33 -08:00 committed by James Bottomley
parent 3a2cdf391b
commit b52df4174d
3 changed files with 63 additions and 6 deletions
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19
drivers/scsi/libsas/sas_ata.c
View File

@ -679,3 +679,22 @@ int sas_ata_eh(struct Scsi_Host *shost, struct list_head *work_q,
return rtn;
}
void sas_ata_schedule_reset(struct domain_device *dev)
{
struct ata_eh_info *ehi;
struct ata_port *ap;
unsigned long flags;
if (!dev_is_sata(dev))
return;
ap = dev->sata_dev.ap;
ehi = &ap->link.eh_info;
spin_lock_irqsave(ap->lock, flags);
ehi->err_mask |= AC_ERR_TIMEOUT;
ehi->action |= ATA_EH_RESET;
ata_port_schedule_eh(ap);
spin_unlock_irqrestore(ap->lock, flags);
}

44
drivers/scsi/libsas/sas_expander.c
View File

@ -28,6 +28,7 @@
#include "sas_internal.h"
#include <scsi/sas_ata.h>
#include <scsi/scsi_transport.h>
#include <scsi/scsi_transport_sas.h>
#include "../scsi_sas_internal.h"
@ -226,12 +227,35 @@ static void sas_set_ex_phy(struct domain_device *dev, int phy_id,
return;
}
/* check if we have an existing attached ata device on this expander phy */
static struct domain_device *sas_ex_to_ata(struct domain_device *ex_dev, int phy_id)
{
struct ex_phy *ex_phy = &ex_dev->ex_dev.ex_phy[phy_id];
struct domain_device *dev;
struct sas_rphy *rphy;
if (!ex_phy->port)
return NULL;
rphy = ex_phy->port->rphy;
if (!rphy)
return NULL;
dev = sas_find_dev_by_rphy(rphy);
if (dev && dev_is_sata(dev))
return dev;
return NULL;
}
#define DISCOVER_REQ_SIZE 16
#define DISCOVER_RESP_SIZE 56
static int sas_ex_phy_discover_helper(struct domain_device *dev, u8 *disc_req,
u8 *disc_resp, int single)
{
struct domain_device *ata_dev = sas_ex_to_ata(dev, single);
int i, res;
disc_req[9] = single;
@ -242,20 +266,30 @@ static int sas_ex_phy_discover_helper(struct domain_device *dev, u8 *disc_req,
disc_resp, DISCOVER_RESP_SIZE);
if (res)
return res;
/* This is detecting a failure to transmit initial
* dev to host FIS as described in section G.5 of
* sas-2 r 04b */
dr = &((struct smp_resp *)disc_resp)->disc;
if (memcmp(dev->sas_addr, dr->attached_sas_addr,
SAS_ADDR_SIZE) == 0) {
sas_printk("Found loopback topology, just ignore it!\n");
return 0;
}
/* This is detecting a failure to transmit initial
* dev to host FIS as described in section J.5 of
* sas-2 r16
*/
if (!(dr->attached_dev_type == 0 &&
dr->attached_sata_dev))
break;
/* In order to generate the dev to host FIS, we
* send a link reset to the expander port */
/* In order to generate the dev to host FIS, we send a
* link reset to the expander port. If a device was
* previously detected on this port we ask libata to
* manage the reset and link recovery.
*/
if (ata_dev) {
sas_ata_schedule_reset(ata_dev);
break;
}
sas_smp_phy_control(dev, single, PHY_FUNC_LINK_RESET, NULL);
/* Wait for the reset to trigger the negotiation */
msleep(500);

6
include/scsi/sas_ata.h
View File

@ -44,7 +44,7 @@ void sas_ata_strategy_handler(struct Scsi_Host *shost);
int sas_ata_eh(struct Scsi_Host *shost, struct list_head *work_q,
struct list_head *done_q);
void sas_probe_sata(struct work_struct *work);
void sas_ata_schedule_reset(struct domain_device *dev);
#else
@ -75,6 +75,10 @@ static inline void sas_probe_sata(struct work_struct *work)
{
}
static inline void sas_ata_schedule_reset(struct domain_device *dev)
{
}
#endif
#endif /* _SAS_ATA_H_ */