On Wed, 25 Oct 2006, David Brownell wrote: > On Tuesday 24 October 2006 9:04 am, Alan Stern wrote: > > When a suspended OHCI controller sees a port's status change, it sets > > both the Root-Hub-Status-Change and the Resume-Detect bits in the > > Interrupt Status register. Processing both these bits, the driver > > tries to resume the root hub twice! > > Thing is, that's not allowed to matter. What the heck is khubd doing > trying to resume twice? No matter what it gets told, or by who, it's > only allowed to do that once.
I didn't say khubd was trying to resume twice. In fact what would happen is that ohci-hcd would first handle the RHSC bit, which entails doing an auto-resume of the root hub. Then it would handle the RD bit by assuming the root hub was still suspended and asking khubd to resume it again. Khubd would not actually carry out that requested resume, but it explains why you got those extra "resume root" messages in your debugging log. And like you said, it didn't matter. Apart from the extra messages in your log. But it was still wrong. > Example: a resume "request" can come top-down, via selective resume > sorts of paths, on one CPU, at the same time a remote wakeup comes > bottom-up from a device. That's _also_ a "resume root twice" case, > so clearly it's got to work correctly. > > Similarly, selective resume of two different root ports would also > be "resume root twice", and also must work correctly. > > I have a very hard time counting this as an OHCI issue ... Of course all those things have to work correctly. If one of them doesn't work quite right, and it's because of a mistake in the ohci-hcd code, that makes it an OHCI issue. Anyway, do you disagree with the main point of that patch (i.e., that RD doesn't need any handling if RHSC is set at the same time)? Alan Stern ------------------------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 _______________________________________________ [email protected] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
