Hi Alan, Thanks for the prompt response.
When an overcurrent condition occurs on a port, to which a device is connected, my understanding is that power on that port will be turned off and hence the device is disconnected. My query is whether khubd, handles this device disconnect event as a USB_PORT_STAT_C_CONNECTION feature? Looking at the current code, it is not very clear, whether khubd handles this condition like an unplug. Pl. correct me if I'm wrong and clarify whether khubd treats it like an unplug. Thanks and Regards, Srivas -----Original Message----- From: Alan Stern [mailto:[EMAIL PROTECTED] Sent: Tuesday, March 28, 2006 10:39 PM To: Srivas Ramgopal (WT01 - Semiconductors & Consumer Electronics) Cc: linux-usb-devel@lists.sourceforge.net Subject: Re: [linux-usb-devel] Queries on root hub functionality On Tue, 28 Mar 2006 [EMAIL PROTECTED] wrote: > Hi all, > > I have the following queries on the root hub functionality: > > How does khubd handle the following conditions? > > 1. When a device is connected and the port is disabled (i.e when the > portchange corresponds to USB_PORT_STAT_C_ENABLE)? khubd treats it like an unplug followed by a replug. Drivers are notified that the device is done, and then the port is reset, the device is enumerated, etc. > 2. When an overcurrent condition occurs on a port, which has a device > connected (i.e. when the portchange corresponds to > USB_PORT_STAT_C_OVERCURRENT)? khubd clears the USB_PORT_C_OVERCURRENT feature and then turns on power to all the ports on the hub. You can read the source code yourself to find these answers. The relevant subroutine is hub_events() in drivers/usb/core/hub.c. 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&kid0944&bid$1720&dat1642 _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
