[PATCH 3.16 134/306] memstick: rtsx_usb_ms: Manage runtime PM when accessing the device

[Ben Hutchings]

3.16.40-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Ulf Hansson <ulf.hansson@xxxxxxxxxx>

commit 9158cb29e7c2f10dd325eb1589f0fe745a271257 upstream.

Accesses to the rtsx usb device, which is the parent of the rtsx memstick
device, must not be done unless it's runtime resumed. This is currently not
the case and it could trigger various errors.

Fix this by properly deal with runtime PM in this regards. This means
making sure the device is runtime resumed, when serving requests via the
->request() callback or changing settings via the ->set_param() callbacks.

Cc: Ritesh Raj Sarraf <rrs@xxxxxxxxxxxxxx>
Cc: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 drivers/memstick/host/rtsx_usb_ms.c | 4 ++++
 1 file changed, 4 insertions(+)

--- a/drivers/memstick/host/rtsx_usb_ms.c
+++ b/drivers/memstick/host/rtsx_usb_ms.c
@@ -524,6 +524,7 @@ static void rtsx_usb_ms_handle_req(struc
 	int rc;
 
 	if (!host->req) {
+		pm_runtime_get_sync(ms_dev(host));
 		do {
 			rc = memstick_next_req(msh, &host->req);
 			dev_dbg(ms_dev(host), "next req %d\n", rc);
@@ -544,6 +545,7 @@ static void rtsx_usb_ms_handle_req(struc
 						host->req->error);
 			}
 		} while (!rc);
+		pm_runtime_put(ms_dev(host));
 	}
 
 }
@@ -570,6 +572,7 @@ static int rtsx_usb_ms_set_param(struct
 	dev_dbg(ms_dev(host), "%s: param = %d, value = %d\n",
 			__func__, param, value);
 
+	pm_runtime_get_sync(ms_dev(host));
 	mutex_lock(&ucr->dev_mutex);
 
 	err = rtsx_usb_card_exclusive_check(ucr, RTSX_USB_MS_CARD);
@@ -635,6 +638,7 @@ static int rtsx_usb_ms_set_param(struct
 	}
 out:
 	mutex_unlock(&ucr->dev_mutex);
+	pm_runtime_put(ms_dev(host));
 
 	/* power-on delay */
 	if (param == MEMSTICK_POWER && value == MEMSTICK_POWER_ON)