The sata on fsl mpc8315e is broken after the commit 8a4aeec8d2d6
("libata/ahci: accommodate tag ordered controllers"). The reason is
that the ata controller on this SoC only implement a queue depth of
16. When issuing the commands in tag order, all the commands in tag
16 ~ 17 are mapped to tag 0 unconditionally and then causes the sata
malfunction. It makes no senses to use a 32 queue in software while
the hardware has less queue depth. This patch provides the function
for libata to adjust the queue depth for a host controller.
Fixes: 8a4aeec8d2d6 ("libata/ahci: accommodate tag ordered controllers")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Kevin Hao <haokexin@xxxxxxxxx>
---
v2: Remove the changes for the ata tag helper functions.
drivers/ata/libata-core.c | 29 ++++++++++++++++++++++++++---
include/linux/libata.h | 3 +++
2 files changed, 29 insertions(+), 3 deletions(-)
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 8f3043165048..c9c51646d8e8 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -4728,14 +4728,14 @@ 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;
+ unsigned int i, tag, max_queue = ap->host->queue_depth;
/* no command while frozen */
if (unlikely(ap->pflags & ATA_PFLAG_FROZEN))
return NULL;
- for (i = 0; i < ATA_MAX_QUEUE; i++) {
- tag = (i + ap->last_tag + 1) % ATA_MAX_QUEUE;
+ for (i = 0; i < max_queue; i++) {
+ tag = (i + ap->last_tag + 1) % max_queue;
/* the last tag is reserved for internal command. */
if (tag == ATA_TAG_INTERNAL)
@@ -5687,6 +5687,27 @@ static void ata_host_release(struct device *gendev, void *res)
}
/**
+ * ata_host_set_queue_depth - set the ATA host controller's queue depth
+ * @host: ATA host to be set for
+ * @queue_depth: the queue depth implemented on this host controller
+ *
+ * We would assume that the ATA host controller has 32 queue depth and
+ * then set the host->queue_depth to 32 by default. If this is not true
+ * for one specific ATA host controller, you need to invoke this function
+ * to set the correct value.
+ */
+int ata_host_set_queue_depth(struct ata_host *host, unsigned int queue_depth)
+{
+ if (!queue_depth || queue_depth > ATA_MAX_QUEUE) {
+ dev_err(host->dev, "Invalid queue depth\n");
+ return -EINVAL;
+ }
+
+ host->queue_depth = queue_depth;
+ return 0;
+}
+
+/**
* ata_host_alloc - allocate and init basic ATA host resources
* @dev: generic device this host is associated with
* @max_ports: maximum number of ATA ports associated with this host
@@ -5731,6 +5752,7 @@ struct ata_host *ata_host_alloc(struct device *dev, int max_ports)
mutex_init(&host->eh_mutex);
host->dev = dev;
host->n_ports = max_ports;
+ host->queue_depth = ATA_MAX_QUEUE;
/* allocate ports bound to this host */
for (i = 0; i < max_ports; i++) {
@@ -6855,6 +6877,7 @@ EXPORT_SYMBOL_GPL(ata_dev_next);
EXPORT_SYMBOL_GPL(ata_std_bios_param);
EXPORT_SYMBOL_GPL(ata_scsi_unlock_native_capacity);
EXPORT_SYMBOL_GPL(ata_host_init);
+EXPORT_SYMBOL_GPL(ata_host_set_queue_depth);
EXPORT_SYMBOL_GPL(ata_host_alloc);
EXPORT_SYMBOL_GPL(ata_host_alloc_pinfo);
EXPORT_SYMBOL_GPL(ata_slave_link_init);
diff --git a/include/linux/libata.h b/include/linux/libata.h
index 5ab4e3a76721..3d912845f7df 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -593,6 +593,7 @@ struct ata_host {
struct device *dev;
void __iomem * const *iomap;
unsigned int n_ports;
+ unsigned int queue_depth;
void *private_data;
struct ata_port_operations *ops;
unsigned long flags;
@@ -1104,6 +1105,8 @@ extern int sata_std_hardreset(struct ata_link *link, unsigned int *class,
unsigned long deadline);
extern void ata_std_postreset(struct ata_link *link, unsigned int *classes);
+extern int ata_host_set_queue_depth(struct ata_host *host,
+ unsigned int queue_depth);
extern struct ata_host *ata_host_alloc(struct device *dev, int max_ports);
extern struct ata_host *ata_host_alloc_pinfo(struct device *dev,
const struct ata_port_info * const * ppi, int n_ports);
--
1.9.3
--
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