On Monday 14 August 2006 12:37 am, s.balamurugan wrote: > > Hello USB USers, > > This bala, i am using 2.6 kernel, i > want to understand the code flow of ehci-hcd.c program. > Can anyone give me the documentation,
UTSL. :) > or give some idea how to start to > understand this program. It's not a "program", it's a "driver" ... a component of a few different complex software stacks. You could start looking at it as an example of a PCI driver, and get one part of the picture. Or as a USB host controller driver, and get a different (and more complete) picture. Of course, to understand the latter you'll have to understand quite a lot about USB as implemented on Linux. Other ways to look at it: as an implementation of a USB hub; as a DMA master; as a system wakeup event source; as something driving a high speed hub's transaction translator. You're going to need to hold a few dozen viewpoints about that code, all at the same time, before you can "understand" it. > what are the steps to follow while analyzing > this program. Turn on all the debug messaging, and watch what happens. Some of the most interesting events in an HCD are: - Device connected to root hub - Device disconnected from root hub - URB submitted by driver (through usbcore) - I/O completion IRQ arrives - URB completes and is given back to it (through usbcore) That shold get you started. - Dave ------------------------------------------------------------------------- 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 _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
