On Sat, Jul 21, 2012 at 11:35 PM, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: > On Sat, 21 Jul 2012, chetan cr123 wrote: > >> Hello, >> Kindly let me know >> how an usb device connection is reported to kernel when we plug an usb cable. >> I see that Udev/ueventd is responsible for that. > > It sounds like you're talking about the device's kernel, not the host's > kernel. > I am talking bout usb device kernel (not the host). but for me tablet/mobile should work as both as 1. As device when we connect to PC. 2. As host when we connect a pendriver or some other device when connected to my tablet. so i was asking about udev/uevent and how the usb plug in reported/detected to kerenl. so that in run time i can decide and load / unload the USB gadget and USB host driver. >> I want to know how exactly usb device will report to (kernel or udev) >> when an device is plugged. > > Answer: Currently connections are not reported. > Ok fine. then kindly let me know how kernel or OS comes to know USB is connected? > There was some discussion about having the gadget core export a > pollable sysfs file that would indicate the current USB connection > state. But nobody has written any code. > >> how can to create an sysfs(node) from gadget driver and this driver >> reports to Udev/uevent when an USB device is connected. >> So that Application can read Uevents of USB plugin and do the >> necessary action (in my case disable the block driver and load usb >> gadget mass storage to communicate with PC -----> SD-card of >> Tablet/mobile) . >> Kindly let me know how can i do this. > > There is no way to do this now. > oh is it. then u mean i cant go with this use case? I am using Android ICS 4.03 source code for our tablet device. I saw in some Samsung phone running on Android 2.3. they have implemented a use case like this. when we use some files(say mp3 ) playing from SD-card------> block driver will come into picture. at the same time when user plugs an USB cable the playing video stops(to say block driver might be unloaded ) to UI they informs user about USB connection and loads gadget driver so that we can read write to SD-card in Tablet(mobile) from computer. This i need to implement on my tablet phone. Kindly let me know how can i do this. > Alan Stern > -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
