> -----Original Message----- > From: kernelnewbies-bounce@xxxxxxxxxxxx > [mailto:kernelnewbies-bounce@xxxxxxxxxxxx] On Behalf Of Code Master > Sent: 19 June 2007 11:19 AM > To: kernelnewbies@xxxxxxxxxxxx > Subject: fails to write to the dummy network device by > outb_p(0xff, 0x378) on the parallel port after successfully > enabling request_region > > I try to write a parallel port kernel module that is able to out all 1 > to the output port of the parallel port, which is connected to a dummy > device that all output port is connected to ground via a set of LED > diode and the most significant bit of the parallel port is also > connected to the interrupt pin, which will trigger an interrupt, as > described in chapter 9 (communicating with hardware) of the book > "Linux Device Drivers (3rd ed)" > It doesn't seem (from a quick glance over you code) that you are attempting to handle the interrupt you will be generating, given the above description. It might be worth attempting to handle this to determine whether the interrupt Is being generated or looking at "dmesg" output, I believe that should have an "unhandled interrupt" message. On the LED front, have you connected the LEDs up the correct way round? Have you used LEDs with built in resistors or connected resistors up to each LED? Also, have you tried testing the LEDs on your device with a 5v power source to ensure that they are functioning? Martyn ---- Martyn Welch Principal Software Engineer Radstone Digital Processing Part of GE Fanuc Embedded Systems Phone: +44 (0) 1327 322748 email: martyn.welch@xxxxxxxxxxxxxx web: www.radstone.com ________________________________________________________________________ This e-mail has been scanned for all viruses by Star.The service is powered by MessageLabs. ________________________________________________________________________ -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
