Hi Alan, Many thanks for the prompt review. On Tue, Feb 25, 2020 at 10:32:32AM -0500, Alan Stern wrote: > On Tue, 25 Feb 2020, Eugeniu Rosca wrote: > > + int r = usb_autopm_get_interface(intf); > > + > > + if (!r) > > + hub->quirk_disable_autosuspend = 1; > > + else > > + dev_dbg(&intf->dev, "disable autosuspend err=%d\n", r); > > } > > > > if (hub_configure(hub, &desc->endpoint[0].desc) >= 0) > > This change is not necessary, because the resume operation cannot fail > at this point (interfaces are always powered-up during probe). Agreed to avoid unneeded complexity. > A better solution would be to call usb_autpm_get_interface_no_resume() > instead. Pushed to https://lore.kernel.org/lkml/20200225183057.31953-1-erosca@xxxxxxxxxxxxxx > > On the other hand, the other places that call > usb_autopm_get_interface() without checking should be audited. Some of > them almost certainly need to be fixed. A quick 'git grep' outputs below list of auditable candidates [1]. With no relevant devices at hand, I would avoid touching these drivers, since oftentimes even legitimate patches introduce regressions w/o testing. If anybody volunteers with testing, I guess it should be quick to either convert usb_autpm_get_interface to *_no_resume variant or handle the return value in place in below instances. [1] (v5.6-rc3) git grep -En "[^=]\s+usb_autopm_get_interface\(" drivers/input/touchscreen/usbtouchscreen.c:1788: usb_autopm_get_interface(intf); drivers/media/usb/stkwebcam/stk-webcam.c:628: usb_autopm_get_interface(dev->interface); drivers/net/usb/hso.c:1308: usb_autopm_get_interface(serial->parent->interface); drivers/net/usb/r8152.c:5231: usb_autopm_get_interface(tp->intf); sound/usb/usx2y/us122l.c:192: usb_autopm_get_interface(iface); -- Best Regards Eugeniu Rosca
