ahci: Cache host controller version

This allows sysfs nodes to read the cached value directly instead of
powering up possibly runtime suspended controller.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

diff --git a/drivers/ata/ahci.h b/drivers/ata/ahci.h
index 167ba7e..70b06bc 100644 (file)
--- a/drivers/ata/ahci.h
+++ b/drivers/ata/ahci.h
@@ -335,6 +335,7 @@ struct ahci_host_priv {
        void __iomem *          mmio;           /* bus-independent mem map */
        u32                     cap;            /* cap to use */
        u32                     cap2;           /* cap2 to use */
+       u32                     version;        /* cached version */
        u32                     port_map;       /* port map to use */
        u32                     saved_cap;      /* saved initial cap */
        u32                     saved_cap2;     /* saved initial cap2 */

diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c
index 513b3fa..8cdf0af 100644 (file)
--- a/drivers/ata/libahci.c
+++ b/drivers/ata/libahci.c
@@ -251,9 +251,8 @@ static ssize_t ahci_show_host_version(struct device *dev,
        struct Scsi_Host *shost = class_to_shost(dev);
        struct ata_port *ap = ata_shost_to_port(shost);
        struct ahci_host_priv *hpriv = ap->host->private_data;
-       void __iomem *mmio = hpriv->mmio;
 
-       return sprintf(buf, "%x\n", readl(mmio + HOST_VERSION));
+       return sprintf(buf, "%x\n", hpriv->version);
 }
 
 static ssize_t ahci_show_port_cmd(struct device *dev,
@@ -509,6 +508,7 @@ void ahci_save_initial_config(struct device *dev, struct ahci_host_priv *hpriv)
        /* record values to use during operation */
        hpriv->cap = cap;
        hpriv->cap2 = cap2;
+       hpriv->version = readl(mmio + HOST_VERSION);
        hpriv->port_map = port_map;
 
        if (!hpriv->start_engine)
@@ -2357,11 +2357,10 @@ static void ahci_port_stop(struct ata_port *ap)
 void ahci_print_info(struct ata_host *host, const char *scc_s)
 {
        struct ahci_host_priv *hpriv = host->private_data;
-       void __iomem *mmio = hpriv->mmio;
        u32 vers, cap, cap2, impl, speed;
        const char *speed_s;
 
-       vers = readl(mmio + HOST_VERSION);
+       vers = hpriv->version;
        cap = hpriv->cap;
        cap2 = hpriv->cap2;
        impl = hpriv->port_map;