On Tue, 18 Apr 2006 [EMAIL PROTECTED] wrote: > Now the problem is PCMCIA powers of the card when it gets the suspend > event. So consider the following case: > > Let the device,port,roothub interface and the Host controller, > which are the nodes of the device tree are not suspened.Now a user > suspends the PCMCIA card. So PCMCIA gets the suspend event and powers of > the card. We have a check in PCMCIA suspend event that whether the Host > controller is suspended or not. So considering the above case we find > that Host controller is not suspended. Now according to LINUX USB > framework, parent node should not be supended if all the child devices > are not suspended. So we thought up three solutions for this. > > First is, fail the suspend event which we cant do because PCMCIA powes > off the card.
You can do it. And you should. > Second is, mark Host Controller as suspended. But I hope this is against > the LINUX USB framework because we should not suspend the host > controller when the bus,port and the device connected to the port are > still active.So you suspend the device connected to the port first, then > the port ,then the roothub interface and then the Host controller. No, don't do this. If those devices aren't already suspended then the PCMCIA socket shouldn't get suspended. > Third is, as the card is physically powered off, we shutdown the > controller. So we thought up doing this. I don't see how. You can't do anything to the controller (shut it down, suspend it, anything) if it doesn't have power. > As you have replied, PCMCIA should not make assumption about its > client. So doing second and third solution are not feasible as we will > be handling/changing HCD stuff from PCMCIA layer. So only thing can be > done is, when PCMCIA gets the suspend event ,it should check whether the > Host Controller is suspended or not. Acoording to the check result, > PCMCIA should handle the suspend event. i.e. it should power off the > card if the Controller is suspended. Otherwise fail the suspend event by > not powering off the card. But PCMCIA behavior is, power off the card > irrespective anything. Then what should be the solution ? The solution is simple and obvious: Fix the PCMCIA layer. Alan Stern ------------------------------------------------------- This SF.Net email is sponsored by xPML, a groundbreaking scripting language that extends applications into web and mobile media. Attend the live webcast and join the prime developer group breaking into this new coding territory! http://sel.as-us.falkag.net/sel?cmd=lnk&kid=110944&bid=241720&dat=121642 _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
