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authorLinus Torvalds <torvalds@linux-foundation.org>2014-07-23 17:39:28 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2014-07-23 17:39:28 -0700
commitea9339e564605286bd04c32c460f8cedc979458c (patch)
tree39dae203b2a6fba41ea84cafee57a3124df82a80 /drivers
parentb292d6b5c4220d527c92316c0d11d16e9895f07e (diff)
parent1a112d10f03e83fb3a2fdc4c9165865dec8a3ca6 (diff)
downloadlinux-ea9339e564605286bd04c32c460f8cedc979458c.tar.bz2
Merge branch 'for-3.16-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata
Pull libata regression fix from Tejun Heo: "The last libata/for-3.16-fixes pull contained a regression introduced by 1871ee134b73 ("libata: support the ata host which implements a queue depth less than 32") which in turn was a fix for a regression introduced earlier while changing queue tag order to accomodate hard drives which perform poorly if tags are not allocated in circular order (ugh...). The regression happens only for SAS controllers making use of libata to serve ATA devices. They don't fill an ata_host field which is used by the new tag allocation function leading to NULL dereference. This patch adds a new intermediate field ata_host->n_tags which is initialized for both SAS and !SAS cases to fix the issue" * 'for-3.16-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata: libata: introduce ata_host->n_tags to avoid oops on SAS controllers
Diffstat (limited to 'drivers')
-rw-r--r--drivers/ata/libata-core.c16
1 files changed, 4 insertions, 12 deletions
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index d19c37a7abc9..677c0c1b03bd 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -4798,9 +4798,8 @@ void swap_buf_le16(u16 *buf, unsigned int buf_words)
static struct ata_queued_cmd *ata_qc_new(struct ata_port *ap)
{
struct ata_queued_cmd *qc = NULL;
- unsigned int i, tag, max_queue;
-
- max_queue = ap->scsi_host->can_queue;
+ unsigned int max_queue = ap->host->n_tags;
+ unsigned int i, tag;
/* no command while frozen */
if (unlikely(ap->pflags & ATA_PFLAG_FROZEN))
@@ -6094,6 +6093,7 @@ void ata_host_init(struct ata_host *host, struct device *dev,
{
spin_lock_init(&host->lock);
mutex_init(&host->eh_mutex);
+ host->n_tags = ATA_MAX_QUEUE - 1;
host->dev = dev;
host->ops = ops;
}
@@ -6175,15 +6175,7 @@ int ata_host_register(struct ata_host *host, struct scsi_host_template *sht)
{
int i, rc;
- /*
- * The max queue supported by hardware must not be greater than
- * ATA_MAX_QUEUE.
- */
- if (sht->can_queue > ATA_MAX_QUEUE) {
- dev_err(host->dev, "BUG: the hardware max queue is too large\n");
- WARN_ON(1);
- return -EINVAL;
- }
+ host->n_tags = clamp(sht->can_queue, 1, ATA_MAX_QUEUE - 1);
/* host must have been started */
if (!(host->flags & ATA_HOST_STARTED)) {