Hello, I'm new to kernel programming. I've been making a kernel testmodule to use motherboards RTC alarm feature. It wakes computer from mechanical shutdown and is not part of acpi or any other that I know of. Problem: It's ok to read register values for alarm, but writing is not. Flags in ioport.h are tested with: flag = pci_resource_flags(&chip, PCI_BASE_ADDRESS_0); printk(KERN_ALERT "\n82471eb: test: flag=%d , 0",flag); and following is set: MEM=on, PREFETCH=on, READONLY=on, UNSET=on, others off. This READONLY seems to be the problem. Module is character driver and device (chip eb82471 from Intel) is: struct pci_dev * chp = ( struct pci_dev * ) pci_find_device(INTEL_VID, CHIP_DID, NULL); it has commands: major = register_chrdev(major, DEVICE_NAME, &fops); pci_enable_device(chp); chip=*chp; pci_read_config_byte(&chip, reg, &ptr); pci_write_config_byte(&chip, reg, ptr); Code is simple but long enough to not to paste in this. I can send the code if necessary. Is for example pci_register command necessary instead of plain char_module registering to enable writes? Do flags have to be changed somehow or has some other driver locked the device? Found that devices struct resource has the flags, but can READONLY be enabled straight from it? Ayway, in real life, should this code be integrated to some other device driver, or is it in bios? Can there be two drivers for the same device? best regards, jnl ________________________________________________________________________ Want to chat instantly with your online friends? Get the FREE Yahoo! Messenger http://mail.messenger.yahoo.co.uk -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
