| Message ID | 0c83d917-678d-d4fc-3225-f2e8355f6280@gmail.com (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
On Wed, 3 Aug 2016, Heiner Kallweit wrote: > 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. Acked-by: Alan Stern <stern@rowland.harvard.edu> There's nothing wrong with this patch; it's a worthwhile thing to do because it can prevent an unnecessary runtime-suspend/resume cycle. Still, it looks like the real problem here may lie in drivers/scsi/hosts.c. Commit bc4f24014de5 ("[SCSI] implement runtime Power Management") added a call to pm_runtime_set_active() in scsi_add_host_with_dma() _after_ device_add() instead of _before_. If that were changed, this problem would not have occurred. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Am 03.08.2016 um 23:25 schrieb Alan Stern: > On Wed, 3 Aug 2016, Heiner Kallweit wrote: > >> 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. > > Acked-by: Alan Stern <stern@rowland.harvard.edu> > > There's nothing wrong with this patch; it's a worthwhile thing to do > because it can prevent an unnecessary runtime-suspend/resume cycle. > > Still, it looks like the real problem here may lie in > drivers/scsi/hosts.c. Commit bc4f24014de5 ("[SCSI] implement runtime > Power Management") added a call to pm_runtime_set_active() in > scsi_add_host_with_dma() _after_ device_add() instead of _before_. > > If that were changed, this problem would not have occurred. > In parallel to this patch I sent another one to address exactly the ordering issue in scsi_add_host_with_dma you mention. The other patch went to Martin and the SCSI mailing list only, sorry. I'll forward it to you for review. Heiner > Alan Stern > > -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/usb/storage/usb.c b/drivers/usb/storage/usb.c index ef2d8cd..8c5f011 100644 --- 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);
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@gmail.com> --- drivers/usb/storage/usb.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)