Messages in this thread | | | Date | Sun, 27 May 2012 10:19:26 +0530 | Subject | Re: Code flow from device connection to device node in /dev creation | From | prasannatsmkumar <> |
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Hi Anil,
If I open a device file (say a printer device) who determines the correct driver and sends the call? How subsequent calls get processed etc. Yes I know the init function will be called while the driver is loaded (while running insmod driver.ko). How a open or write call comes to the driver from user space? Who keeps track of the driver's internal data (*dev) and sends that while calling methods in the driver? I am more interested in things like that.
Thanks, Prasanna Kumar
On Sun, May 27, 2012 at 7:37 AM, Anil Nair <anilcoll90@gmail.com> wrote: > Hi Prasanna, > > On Fri, May 25, 2012 at 8:13 PM, prasannatsmkumar > <prasannatsmkumar@gmail.com> wrote: >> Thanks for your recommendation but I have went through the USB 2.0 >> specification and also had a chance to glance Linux USB Stack Design >> Book. I am interested in software side - how things are going in >> Linux. Upon connecting a mass storage device or USB keyboard is >> connected how things works - the flow and the stack. Including the >> user space tools that gets involved. > > Try compiling the linux kernel CONFIG_USB_DEBUG enabled. You can learn > a lot by observing the kernel log, to view kernel log type dmesg. Try > using usbmon Documentation can be found in > Documentation/usb/usbmon.txt, i hope you have tried that. > Typically a driver starts from the probe function checks if > the device is listed in its table "usb_device_id", try working from > the probe function. A good way to start is the usb-skeleton.c present > in linux kernel source "drivers/usb/usb-skeleton.c". > Also working of a kernel module differ the life cycle of > the kernel module start from _init function when it is called or > inserted to kernel using "insmod" of "modprobe". > And make sure you use reply-to-all when in the mailing > list. :). So, that others can help you too. > > > > -- > Regards, > Anil Nair -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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