Merge branch 'for-3.15-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata

Pull libata fixes from Tejun Heo:
 "Dan updated tag allocation to accomodate devices which choke when tags
  jump back and forth.  Quite a few ahci MSI related fixes.  A couple
  config dependency fixes and other misc fixes"

* 'for-3.15-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata:
  libata/ahci: accommodate tag ordered controllers
  ahci: Do not receive interrupts sent by dummy ports
  ahci: Use pci_enable_msi_exact() instead of pci_enable_msi_range()
  ahci: Ensure "MSI Revert to Single Message" mode is not enforced
  ahci: do not request irq for dummy port
  pata_samsung_cf: fix ata_host_activate() failure handling
  pata_arasan_cf: fix ata_host_activate() failure handling
  ata: fix i.MX AHCI driver dependencies
  pata_at91: fix ata_host_activate() failure handling
  libata: Update queued trim blacklist for M5x0 drives
  libata: make AHCI_XGENE depend on PHY_XGENE

1 files changed, 17 insertions, 10 deletions

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index c19734d96d7e..943cc8b83e59 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -4224,8 +4224,10 @@ static const struct ata_blacklist_entry ata_device_blacklist [] = {
 	{ "PIONEER DVD-RW  DVR-216D",	NULL,	ATA_HORKAGE_NOSETXFER },
 
 	/* devices that don't properly handle queued TRIM commands */
-	{ "Micron_M500*",		NULL,	ATA_HORKAGE_NO_NCQ_TRIM, },
-	{ "Crucial_CT???M500SSD*",	NULL,	ATA_HORKAGE_NO_NCQ_TRIM, },
+	{ "Micron_M500*",		"MU0[1-4]*",	ATA_HORKAGE_NO_NCQ_TRIM, },
+	{ "Crucial_CT???M500SSD*",	"MU0[1-4]*",	ATA_HORKAGE_NO_NCQ_TRIM, },
+	{ "Micron_M550*",		NULL,		ATA_HORKAGE_NO_NCQ_TRIM, },
+	{ "Crucial_CT???M550SSD*",	NULL,		ATA_HORKAGE_NO_NCQ_TRIM, },
 
 	/*
 	 * Some WD SATA-I drives spin up and down erratically when the link
@@ -4792,21 +4794,26 @@ 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;
+	unsigned int i, tag;
 
 	/* no command while frozen */
 	if (unlikely(ap->pflags & ATA_PFLAG_FROZEN))
 		return NULL;
 
-	/* the last tag is reserved for internal command. */
-	for (i = 0; i < ATA_MAX_QUEUE - 1; i++)
-		if (!test_and_set_bit(i, &ap->qc_allocated)) {
-			qc = __ata_qc_from_tag(ap, i);
+	for (i = 0; i < ATA_MAX_QUEUE; i++) {
+		tag = (i + ap->last_tag + 1) % ATA_MAX_QUEUE;
+
+		/* the last tag is reserved for internal command. */
+		if (tag == ATA_TAG_INTERNAL)
+			continue;
+
+		if (!test_and_set_bit(tag, &ap->qc_allocated)) {
+			qc = __ata_qc_from_tag(ap, tag);
+			qc->tag = tag;
+			ap->last_tag = tag;
 			break;
 		}
-
-	if (qc)
-		qc->tag = i;
+	}
 
 	return qc;
 }