[SCSI] aic7xxx/aic79xx: fix module removal path not to panic

In these drivers, scsi_remove_host() is called too late, at the point
it is called, the driver has already shut down too far to accept any
I/O that the shutdown might generate.  Any generated I/O actually
triggers a panic.

Fix this by calling scsi_remove_host() as early as possible and not
calling scsi_host_put() until just before we kfree the ahc_softc.
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

drivers/scsi/aic7xxx/aic7770_osm.c

@@ -112,6 +112,9 @@ aic7770_remove(struct device *dev)
 	struct ahc_softc *ahc = dev_get_drvdata(dev);
 	u_long s;
 
+	if (ahc->platform_data && ahc->platform_data->host)
+			scsi_remove_host(ahc->platform_data->host);
+
 	ahc_lock(ahc, &s);
 	ahc_intr_enable(ahc, FALSE);
 	ahc_unlock(ahc, &s);

drivers/scsi/aic7xxx/aic79xx_osm.c

@@ -1192,11 +1192,6 @@ ahd_platform_free(struct ahd_softc *ahd)
 	int i, j;
 
 	if (ahd->platform_data != NULL) {
-		if (ahd->platform_data->host != NULL) {
-			scsi_remove_host(ahd->platform_data->host);
-			scsi_host_put(ahd->platform_data->host);
-		}
-
 		/* destroy all of the device and target objects */
 		for (i = 0; i < AHD_NUM_TARGETS; i++) {
 			starget = ahd->platform_data->starget[i];
@@ -1226,6 +1221,9 @@ ahd_platform_free(struct ahd_softc *ahd)
 			release_mem_region(ahd->platform_data->mem_busaddr,
 					   0x1000);
 		}
+		if (ahd->platform_data->host)
+			scsi_host_put(ahd->platform_data->host);
+
 		free(ahd->platform_data, M_DEVBUF);
 	}
 }

drivers/scsi/aic7xxx/aic79xx_osm_pci.c

@@ -95,6 +95,9 @@ ahd_linux_pci_dev_remove(struct pci_dev *pdev)
 	struct ahd_softc *ahd = pci_get_drvdata(pdev);
 	u_long s;
 
+	if (ahd->platform_data && ahd->platform_data->host)
+			scsi_remove_host(ahd->platform_data->host);
+
 	ahd_lock(ahd, &s);
 	ahd_intr_enable(ahd, FALSE);
 	ahd_unlock(ahd, &s);

drivers/scsi/aic7xxx/aic7xxx_osm.c

@@ -1209,11 +1209,6 @@ ahc_platform_free(struct ahc_softc *ahc)
 	int i, j;
 
 	if (ahc->platform_data != NULL) {
-		if (ahc->platform_data->host != NULL) {
-			scsi_remove_host(ahc->platform_data->host);
-			scsi_host_put(ahc->platform_data->host);
-		}
-
 		/* destroy all of the device and target objects */
 		for (i = 0; i < AHC_NUM_TARGETS; i++) {
 			starget = ahc->platform_data->starget[i];
@@ -1242,6 +1237,9 @@ ahc_platform_free(struct ahc_softc *ahc)
 					   0x1000);
 		}
 
+		if (ahc->platform_data->host)
+			scsi_host_put(ahc->platform_data->host);
+
 		free(ahc->platform_data, M_DEVBUF);
 	}
 }

drivers/scsi/aic7xxx/aic7xxx_osm_pci.c

@@ -143,6 +143,9 @@ ahc_linux_pci_dev_remove(struct pci_dev *pdev)
 	struct ahc_softc *ahc = pci_get_drvdata(pdev);
 	u_long s;
 
+	if (ahc->platform_data && ahc->platform_data->host)
+			scsi_remove_host(ahc->platform_data->host);
+
 	ahc_lock(ahc, &s);
 	ahc_intr_enable(ahc, FALSE);
 	ahc_unlock(ahc, &s);