Linux - HardwareThis forum is for Hardware issues.
Having trouble installing a piece of hardware? Want to know if that peripheral is compatible with Linux?
Welcome to LinuxQuestions.org, a friendly and active Linux Community.
You are currently viewing LQ as a guest. By joining our community you will have the ability to post topics, receive our newsletter, use the advanced search, subscribe to threads and access many other special features. Registration is quick, simple and absolutely free. Join our community today!
Note that registered members see fewer ads, and ContentLink is completely disabled once you log in.
Since IRQ 7 is traditionally used for the parallel printer port, perhaps that's what it's disabling (either the port itself, if you are not using it, as this IRQ is often set in the BIOS, or simply the setting, as it would need to be overridden so that your SATA controller could use it).
Originally posted by motub Since IRQ 7 is traditionally used for the parallel printer port, perhaps that's what it's disabling (either the port itself, if you are not using it, as this IRQ is often set in the BIOS, or simply the setting, as it would need to be overridden so that your SATA controller could use it).
Yes, but that comes after the "original" IRQ 7 was disabled, so presumably it is re-enabled.
I was just suggesting why that might be-- because your BIOS, for example, is set to use IRQ 7 for an ECP parallel port, and so the kernel read that setting, but 1) you don't have or use the parallel port (so IRQ 7 was not "claimed" by an active device), and 2) the SATA controller then came along and said, "btw, I need IRQ 7," so that IRQ was then enabled (since it was free and unclaimed) and given to it.
I can't see into your BIOS naturally, but the parallel port has been "hard-coded" to use IRQ 7 for as long as I've been using computers (over 10 years). Now that computers generally do not use the parallel port, but instead hook the devices that used to use that port (printers, scanners) to USB ports instead, IRQ 7 is in a rather odd position, since the motherboard still does probably have a printer port, and if that port is not specifically turned off/disabled as not used in the BIOS, IRQ 7 will most likely be assigned to it automatically. However, the printer port is unlikely to be used, which would waste an IRQ that is desperately needed, given the large number of devices on any normal system. Not to mention that if it came to which was more important, the SATA controller beats any parallel port devices by a long shot, even if you had a parallel port device connected.
It could even be that the SATA controller is "hard-coded" to redirect IRQ 7 to itself if no parallel port device is detected in a probe, rather than fight with your video card, sound card and network card for sharing space on IRQs 9-11 (which is where most "extra" devices-- meaning devices not soldered to the motherboard as ports and IDE controllers are-- usually wind up).
Obviously everything is working OK, so it's just a question of interest, which is why I answered with my best speculation on what might be happening.