Mike> I understand a kernel driver, is a driver that Linus, et al, Mike> have coded into the kernel, so if i have a peice of hardware, Mike> and I compile a kernel with that device's driver turned on, then Mike> my device will work. Mike> If i build that kernel driver as a module, the driver remains Mike> outside the kernel, but still availible for use. As a module I Mike> can rmmod or insmod when i need to use the device. You're mixing up two different things. Almost all drivers which are shipped with the linux kernel can be compiled in one of two ways: into the kernel, or as a module which can be loaded/unloaded at run-time. So if you have a driver and compile it into the kernel, you should see some output from 'dmesg' showing you what was deteced on bootup of the kernel. Mike> My foggy'ness comes from a few things. Mike> 1. if the driver is built into the kernel, will it show up in lsmod? No, because lsmod only shows loaded modules, not modules which are available for loading. It also doesn't show up drivers which are compiled into the kernel directly. Mike> 2. if the driver does not show up in lsmod, how do i know if Mike> its loaded? Check the output of the 'dmesg' command after a full reboot with your driver. You should at least see something about that driver, whether or not it detects any devices. Mike> 3. weather it's a built in driver or a module, how do i Mike> associate the driver (or module) with a particular device? It depends on the driver, but generally they go by PCI device ID to determine which hardware they can access. Mike> 4. if the device does not have a driver in the kernel, I cannot Mike> build a custom kernel to include it, nor can I build it as a Mike> module from the kernel source. So: This makes no sense here. Of course you can build a custom kernel with a driver shipped outside of the normal linux kernel. Mike> 5. if I get the driver from the vendor, it will build a module Mike> for me, based on my kernel-source or kernel-headers??? Then Mike> what? again, see #3: how do i associate the module with my Mike> device? If you are given vendor provided driver, you can have several issues to address here. One, it needs to match your running kernel image if it's a completely binary only module. Not a great idea in my book. If there is a binary core, but an source code wrapper section, then you'll need to compile the module against the installed kernel's headers. Not hard, the vendor should go into all these details. Mike> This is a general linux quandry, but this time i have a debian Mike> stable install and have inserted a QLogic HBA. lsmod does show Mike> qla2xxx, but it doesn't seem to be functioning as it isn't Mike> logging into the fiber switch. Check the output of 'dmesg' and see what it says. You might need to check the logs on the switch as well to make sure that you're allowing the system holding the adapter is bringing it online and that the switch is seeing it try to login. Feel free to post details and such here, the more the better! John