libata-pmp-prep: implement ATA_LFLAG_DISABLED

Implement ATA_LFLAG_DISABLED.  The flag indicates the link is disabled
due to EH recovery failure.  While a link is disabled, no EH action is
taken on the link and suspend/resume become noop too.

This will be used by PMP links to manage failed links.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index 8f8ed4dfb1711bdd8041690b4ebf4198aa46dc31..fbbf791639006fb9b9044f60bff679a0915a3120 100644 (file)
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -1308,6 +1308,7 @@ static void ata_eh_analyze_serror(struct ata_link *link)
        struct ata_eh_context *ehc = &link->eh_context;
        u32 serror = ehc->i.serror;
        unsigned int err_mask = 0, action = 0;
+       u32 hotplug_mask;
 
        if (serror & SERR_PERSISTENT) {
                err_mask |= AC_ERR_ATA_BUS;
@@ -1326,7 +1327,20 @@ static void ata_eh_analyze_serror(struct ata_link *link)
                err_mask |= AC_ERR_SYSTEM;
                action |= ATA_EH_HARDRESET;
        }
-       if (serror & (SERR_PHYRDY_CHG | SERR_DEV_XCHG))
+
+       /* Determine whether a hotplug event has occurred.  Both
+        * SError.N/X are considered hotplug events for enabled or
+        * host links.  For disabled PMP links, only N bit is
+        * considered as X bit is left at 1 for link plugging.
+        */
+       hotplug_mask = 0;
+
+       if (!(link->flags & ATA_LFLAG_DISABLED) || ata_is_host_link(link))
+               hotplug_mask = SERR_PHYRDY_CHG | SERR_DEV_XCHG;
+       else
+               hotplug_mask = SERR_PHYRDY_CHG;
+
+       if (serror & hotplug_mask)
                ata_ehi_hotplugged(&ehc->i);
 
        ehc->i.err_mask |= err_mask;
@@ -2227,6 +2241,10 @@ static int ata_eh_skip_recovery(struct ata_link *link)
        struct ata_eh_context *ehc = &link->eh_context;
        struct ata_device *dev;
 
+       /* skip disabled links */
+       if (link->flags & ATA_LFLAG_DISABLED)
+               return 1;
+
        /* thaw frozen port, resume link and recover failed devices */
        if ((link->ap->pflags & ATA_PFLAG_FROZEN) ||
            (ehc->i.flags & ATA_EHI_RESUME_LINK) || ata_link_nr_enabled(link))
@@ -2327,6 +2345,7 @@ int ata_eh_recover(struct ata_port *ap, ata_prereset_fn_t prereset,
        struct ata_device *dev;
        int nr_failed_devs, nr_disabled_devs;
        int reset, rc;
+       unsigned long flags;
 
        DPRINTK("ENTER\n");
 
@@ -2334,6 +2353,15 @@ int ata_eh_recover(struct ata_port *ap, ata_prereset_fn_t prereset,
        ata_port_for_each_link(link, ap) {
                struct ata_eh_context *ehc = &link->eh_context;
 
+               /* re-enable link? */
+               if (ehc->i.action & ATA_EH_ENABLE_LINK) {
+                       ata_eh_about_to_do(link, NULL, ATA_EH_ENABLE_LINK);
+                       spin_lock_irqsave(ap->lock, flags);
+                       link->flags &= ~ATA_LFLAG_DISABLED;
+                       spin_unlock_irqrestore(ap->lock, flags);
+                       ata_eh_done(link, NULL, ATA_EH_ENABLE_LINK);
+               }
+
                ata_link_for_each_dev(dev, link) {
                        if (link->flags & ATA_LFLAG_NO_RETRY)
                                ehc->tries[dev->devno] = 1;

diff --git a/include/linux/libata.h b/include/linux/libata.h
index adeee7397cdb35517a852f737bf025b9c16eb896..2bd1d26c9c8dc7c3184ebd84db3a3a126a1ae290 100644 (file)
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -170,6 +170,7 @@ enum {
        ATA_LFLAG_ASSUME_SEMB   = (1 << 4), /* assume SEMB class */
        ATA_LFLAG_ASSUME_CLASS  = ATA_LFLAG_ASSUME_ATA | ATA_LFLAG_ASSUME_SEMB,
        ATA_LFLAG_NO_RETRY      = (1 << 5), /* don't retry this link */
+       ATA_LFLAG_DISABLED      = (1 << 6), /* link is disabled */
 
        /* struct ata_port flags */
        ATA_FLAG_SLAVE_POSS     = (1 << 0), /* host supports slave dev */
@@ -289,6 +290,7 @@ enum {
        ATA_EH_REVALIDATE       = (1 << 0),
        ATA_EH_SOFTRESET        = (1 << 1),
        ATA_EH_HARDRESET        = (1 << 2),
+       ATA_EH_ENABLE_LINK      = (1 << 3),
 
        ATA_EH_RESET_MASK       = ATA_EH_SOFTRESET | ATA_EH_HARDRESET,
        ATA_EH_PERDEV_MASK      = ATA_EH_REVALIDATE,
@@ -999,6 +1001,7 @@ static inline void ata_ehi_hotplugged(struct ata_eh_info *ehi)
 {
        ata_ehi_schedule_probe(ehi);
        ehi->flags |= ATA_EHI_HOTPLUGGED;
+       ehi->action |= ATA_EH_ENABLE_LINK;
        ehi->err_mask |= AC_ERR_ATA_BUS;
 }