libata: implement no[hs]rst force params

Implement force params nohrst, nosrst and norst.  This is to work
around reset related problems and ease debugging.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index a897646..1150444 100644 (file)
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1074,6 +1074,9 @@ and is between 256 and 4096 characters. It is defined in the file
 
                        * [no]ncq: Turn on or off NCQ.
 
+                       * nohrst, nosrst, norst: suppress hard, soft
+                          and both resets.
+
                        If there are multiple matching configurations changing
                        the same attribute, the last one is used.
 

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 5ba96c5..dddcb9f 100644 (file)
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -104,6 +104,7 @@ struct ata_force_param {
        unsigned long   xfer_mask;
        unsigned int    horkage_on;
        unsigned int    horkage_off;
+       unsigned int    lflags;
 };
 
 struct ata_force_ent {
@@ -196,22 +197,23 @@ void ata_force_cbl(struct ata_port *ap)
 }
 
 /**
- *     ata_force_spd_limit - force SATA spd limit according to libata.force
+ *     ata_force_link_limits - force link limits according to libata.force
  *     @link: ATA link of interest
  *
- *     Force SATA spd limit according to libata.force and whine about
- *     it.  When only the port part is specified (e.g. 1:), the limit
- *     applies to all links connected to both the host link and all
- *     fan-out ports connected via PMP.  If the device part is
- *     specified as 0 (e.g. 1.00:), it specifies the first fan-out
- *     link not the host link.  Device number 15 always points to the
- *     host link whether PMP is attached or not.
+ *     Force link flags and SATA spd limit according to libata.force
+ *     and whine about it.  When only the port part is specified
+ *     (e.g. 1:), the limit applies to all links connected to both
+ *     the host link and all fan-out ports connected via PMP.  If the
+ *     device part is specified as 0 (e.g. 1.00:), it specifies the
+ *     first fan-out link not the host link.  Device number 15 always
+ *     points to the host link whether PMP is attached or not.
  *
  *     LOCKING:
  *     EH context.
  */
-static void ata_force_spd_limit(struct ata_link *link)
+static void ata_force_link_limits(struct ata_link *link)
 {
+       bool did_spd = false;
        int linkno, i;
 
        if (ata_is_host_link(link))
@@ -228,13 +230,22 @@ static void ata_force_spd_limit(struct ata_link *link)
                if (fe->device != -1 && fe->device != linkno)
                        continue;
 
-               if (!fe->param.spd_limit)
-                       continue;
+               /* only honor the first spd limit */
+               if (!did_spd && fe->param.spd_limit) {
+                       link->hw_sata_spd_limit = (1 << fe->param.spd_limit) - 1;
+                       ata_link_printk(link, KERN_NOTICE,
+                                       "FORCE: PHY spd limit set to %s\n",
+                                       fe->param.name);
+                       did_spd = true;
+               }
 
-               link->hw_sata_spd_limit = (1 << fe->param.spd_limit) - 1;
-               ata_link_printk(link, KERN_NOTICE,
-                       "FORCE: PHY spd limit set to %s\n", fe->param.name);
-               return;
+               /* let lflags stack */
+               if (fe->param.lflags) {
+                       link->flags |= fe->param.lflags;
+                       ata_link_printk(link, KERN_NOTICE,
+                                       "FORCE: link flag 0x%x forced -> 0x%x\n",
+                                       fe->param.lflags, link->flags);
+               }
        }
 }
 
@@ -5200,7 +5211,7 @@ int sata_link_init_spd(struct ata_link *link)
        if (spd)
                link->hw_sata_spd_limit &= (1 << spd) - 1;
 
-       ata_force_spd_limit(link);
+       ata_force_link_limits(link);
 
        link->sata_spd_limit = link->hw_sata_spd_limit;
 
@@ -5991,6 +6002,9 @@ static int __init ata_parse_force_one(char **cur,
                { "udma133",    .xfer_mask      = 1 << (ATA_SHIFT_UDMA + 6) },
                { "udma/133",   .xfer_mask      = 1 << (ATA_SHIFT_UDMA + 6) },
                { "udma7",      .xfer_mask      = 1 << (ATA_SHIFT_UDMA + 7) },
+               { "nohrst",     .lflags         = ATA_LFLAG_NO_HRST },
+               { "nosrst",     .lflags         = ATA_LFLAG_NO_SRST },
+               { "norst",      .lflags         = ATA_LFLAG_NO_HRST | ATA_LFLAG_NO_SRST },
        };
        char *start = *cur, *p = *cur;
        char *id, *val, *endp;

diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index 58bdc53..a570ca4 100644 (file)
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -2210,6 +2210,10 @@ int ata_eh_reset(struct ata_link *link, int classify,
         */
        while (ata_eh_reset_timeouts[max_tries] != ULONG_MAX)
                max_tries++;
+       if (link->flags & ATA_LFLAG_NO_HRST)
+               hardreset = NULL;
+       if (link->flags & ATA_LFLAG_NO_SRST)
+               softreset = NULL;
 
        now = jiffies;
        deadline = ata_deadline(ehc->last_reset, ATA_EH_RESET_COOL_DOWN);

diff --git a/include/linux/libata.h b/include/linux/libata.h
index 06b8033..5340d4c 100644 (file)
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -163,6 +163,7 @@ enum {
        ATA_DEV_NONE            = 9,    /* no device */
 
        /* struct ata_link flags */
+       ATA_LFLAG_NO_HRST       = (1 << 1), /* avoid hardreset */
        ATA_LFLAG_NO_SRST       = (1 << 2), /* avoid softreset */
        ATA_LFLAG_ASSUME_ATA    = (1 << 3), /* assume ATA class */
        ATA_LFLAG_ASSUME_SEMB   = (1 << 4), /* assume SEMB class */