Messages in this thread | | | Subject | Re: question about usb_rebind_intf | From | Mathias Nyman <> | Date | Fri, 17 Nov 2017 19:45:35 +0200 |
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On 17.11.2017 19:09, Greg Kroah-Hartman wrote: > On Fri, Nov 17, 2017 at 09:35:51AM -0700, Jerry Snitselaar wrote: >> Should this skip warning that the rebind failed if device_attach >> is returning -EPROBE_DEFER? If I do something like 'rtcwake -m mem -s 30' >> on a laptop I have here I will see a couple "rebind failed: -517" messages >> as it comes back out of suspend. Since the device probe eventually happens >> once probes are not deferred wondering if this warning this be given in that >> case. >> >> >> diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c >> index 64262a9a8829..5d3408010112 100644 >> --- a/drivers/usb/core/driver.c >> +++ b/drivers/usb/core/driver.c >> @@ -1070,7 +1070,7 @@ static void usb_rebind_intf(struct usb_interface *intf) >> if (!intf->dev.power.is_prepared) { >> intf->needs_binding = 0; >> rc = device_attach(&intf->dev); >> - if (rc < 0) >> + if (rc < 0 && rc != -EPROBE_DEFER) >> dev_warn(&intf->dev, "rebind failed: %d\n", rc); >> } >> } > > What USB driver is returning -EPROBE_DEFER to cause this to be an issue? > Shouldn't that really only be for "platform" drivers and the like? USB > interface drivers should all be "self-contained" within reason. >
I see this as well with btusb driver in resume if port was reset.
drivers/base/dd.c really_probe() returns -EPROBE_DEFER if it's called before device_unblock_probing() is called.
drivers/base/power/main/dpm_complete() will unlock probing after it has finished resuming all devices and called all the pm_ops .complete callbacks.
The usb_device_pm_ops .complete callback will try to rebind the interface driver if device was reset at resume, leading to them -EPROBE_DEFER.
I guess we either need to rework a few things, or remove that warning.
-Mathias
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