[PATCH 4.8 01/37] usb: storage: fix runtime pm issue in usb_stor_probe2

From: Greg Kroah-Hartman
Date: Fri Oct 14 2016 - 08:27:41 EST


4.8-stable review patch. If anyone has any objections, please let me know.

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

From: Heiner Kallweit <hkallweit1@xxxxxxxxx>

commit a094760b9a77f81ee3cbeff323ee77c928f41106 upstream.

Since commit 71723f95463d "PM / runtime: print error when activating a
child to unactive parent" I see the following error message:

scsi host2: usb-storage 1-3:1.0
scsi host2: runtime PM trying to activate child device host2 but parent
(1-3:1.0) is not active

Digging into it it seems to be related to the problem described in the
commit message for cd998ded5c12 "i2c: designware: Prevent runtime
suspend during adapter registration" as scsi_add_host also calls
device_add and after the call to device_add the parent device is
suspended.

Fix this by using the approach from the mentioned commit and getting
the runtime pm reference before calling scsi_add_host.

Signed-off-by: Heiner Kallweit <hkallweit1@xxxxxxxxx>
Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/usb/storage/usb.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

--- a/drivers/usb/storage/usb.c
+++ b/drivers/usb/storage/usb.c
@@ -1070,17 +1070,17 @@ int usb_stor_probe2(struct us_data *us)
result = usb_stor_acquire_resources(us);
if (result)
goto BadDevice;
+ usb_autopm_get_interface_no_resume(us->pusb_intf);
snprintf(us->scsi_name, sizeof(us->scsi_name), "usb-storage %s",
dev_name(&us->pusb_intf->dev));
result = scsi_add_host(us_to_host(us), dev);
if (result) {
dev_warn(dev,
"Unable to add the scsi host\n");
- goto BadDevice;
+ goto HostAddErr;
}

/* Submit the delayed_work for SCSI-device scanning */
- usb_autopm_get_interface_no_resume(us->pusb_intf);
set_bit(US_FLIDX_SCAN_PENDING, &us->dflags);

if (delay_use > 0)
@@ -1090,6 +1090,8 @@ int usb_stor_probe2(struct us_data *us)
return 0;

/* We come here if there are any problems */
+HostAddErr:
+ usb_autopm_put_interface_no_suspend(us->pusb_intf);
BadDevice:
usb_stor_dbg(us, "storage_probe() failed\n");
release_everything(us);