ahci_platform: perform platform exit in host_stop() hook

AHCI platform devices may provide an exit() routine, via
ahci_platform_data, that powers off the SATA core. Such a routine should
be executed from the ata_port_operations host_stop() hook. That way, the
ATA subsystem can perform any last-minute hardware cleanup (via devres,
for example), then trigger the power-off at the appropriate time.

This patch fixes bus errors triggered during module removal or device
unbinding, seen on an SoC SATA core.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

1 files changed, 23 insertions, 7 deletions

diff --git a/drivers/ata/ahci_platform.c b/drivers/ata/ahci_platform.c
index fbbfa2bccbcd..5aa4309d4481 100644
--- a/drivers/ata/ahci_platform.c
+++ b/drivers/ata/ahci_platform.c
@@ -25,6 +25,8 @@
 #include <linux/ahci_platform.h>
 #include "ahci.h"
 
+static void ahci_host_stop(struct ata_host *host);
+
 enum ahci_type {
         AHCI,           /* standard platform ahci */
         IMX53_AHCI,     /* ahci on i.mx53 */
@@ -47,6 +49,15 @@ static struct platform_device_id ahci_devtype[] = {
 };
 MODULE_DEVICE_TABLE(platform, ahci_devtype);
 
+struct ata_port_operations ahci_platform_ops = {
+        .inherits       = &ahci_ops,
+        .host_stop      = ahci_host_stop,
+};
+
+struct ata_port_operations ahci_platform_retry_srst_ops = {
+        .inherits       = &ahci_pmp_retry_srst_ops,
+        .host_stop      = ahci_host_stop,
+};
 
 static const struct ata_port_info ahci_port_info[] = {
         /* by features */
@@ -54,20 +65,20 @@ static const struct ata_port_info ahci_port_info[] = {
                 .flags          = AHCI_FLAG_COMMON,
                 .pio_mask       = ATA_PIO4,
                 .udma_mask      = ATA_UDMA6,
-                .port_ops       = &ahci_ops,
+                .port_ops       = &ahci_platform_ops,
         },
         [IMX53_AHCI] = {
                 .flags          = AHCI_FLAG_COMMON,
                 .pio_mask       = ATA_PIO4,
                 .udma_mask      = ATA_UDMA6,
-                .port_ops       = &ahci_pmp_retry_srst_ops,
+                .port_ops       = &ahci_platform_retry_srst_ops,
         },
         [STRICT_AHCI] = {
                 AHCI_HFLAGS     (AHCI_HFLAG_DELAY_ENGINE),
                 .flags          = AHCI_FLAG_COMMON,
                 .pio_mask       = ATA_PIO4,
                 .udma_mask      = ATA_UDMA6,
-                .port_ops       = &ahci_ops,
+                .port_ops       = &ahci_platform_ops,
         },
 };
 
@@ -221,12 +232,19 @@ free_clk:
 static int __devexit ahci_remove(struct platform_device *pdev)
 {
         struct device *dev = &pdev->dev;
-        struct ahci_platform_data *pdata = dev_get_platdata(dev);
         struct ata_host *host = dev_get_drvdata(dev);
-        struct ahci_host_priv *hpriv = host->private_data;
 
         ata_host_detach(host);
 
+        return 0;
+}
+
+static void ahci_host_stop(struct ata_host *host)
+{
+        struct device *dev = host->dev;
+        struct ahci_platform_data *pdata = dev_get_platdata(dev);
+        struct ahci_host_priv *hpriv = host->private_data;
+
         if (pdata && pdata->exit)
                 pdata->exit(dev);
 
@@ -234,8 +252,6 @@ static int __devexit ahci_remove(struct platform_device *pdev)
                 clk_disable_unprepare(hpriv->clk);
                 clk_put(hpriv->clk);
         }
-
-        return 0;
 }
 
 #ifdef CONFIG_PM_SLEEP