Hi everybody, I have an IT8705F SuperIO on my motherboard and everything is working but the voltage/temperature sensors (running kernel 2.6.21.3). I read the specs and figured out how to get direct access to the chip: you can setup it through IO port 0x2e (or 0x4e), and decide where the sensors will be in the IO space (default: 0x290). Everything about it is fine, but reading from (or writing to) ports 0x290-0x297 is useless (all I get is 0xff).
With a few lines of code I canged base port to 0xc00 and now it works, it87.ko loads and works flawlessly; this puzzled me, so I tried a 2.4 kernel and discovered it just works, no need to change the base port. I also look directly at the ports with DOS DEBUG and got the same results. A few facts: 1) The IT8705F is fine (BIOS, Win98, linux 2.4 are just happy about it); 2) it works with kernel 2.4.33.3, it doesn't with 2.6.17.13; 3) disabling ACPI, hotplug and everything I tried is irrelevant; 4) the bug is NOT related to the it87 driver: reading the ports right after a reboot (with no modules loaded) just returns 0xff, while I'm sure I should get reasonable values (I read the whole spec, so I'm not messing around with the wrong ports or anything like that); the it87 driver, however, finds the chip, but when it understands it's unable to do anything useful, it quits (ENODEV); after altering the io port to something different, it runs just fine; 5) the io ports are not used by other devices. From /proc/ioports: 0201-0201 : ns558-pnp 0330-0331 : MPU401 UART [...] 03f8-03ff : serial 0cf8-0cff : PCI conf1 so 0x290-0x297 should be as good as 0xc00-0xc07; 6) I have no idea of what, in the kernel, can cause such a behaviour ;) I'm no kernel expert, but this sounds quite like an interesting problem to me! I can produce a detailed report, if you need more informations, but I'm not subscribed to the lkml, so please CC: me any answer. Ciao, Federico Di Dio - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
