On 10/30/23 07:19, Alan Stern wrote: > On Mon, Oct 30, 2023 at 09:30:15AM +0100, Greg KH wrote: >> On Mon, Oct 30, 2023 at 10:15:30AM +0200, ariel marcovitch wrote: >>>> Please realize that usb-serial console was the result of me loosing a >>>> drunken bet. It's amazing it works at all. For "fake" devices like >>> LOL your drunken bet was quite helpful to some people >>> Because modern PCs come without a serial port, I wanted to use it to >>> see early logs on my crashing kernel without having to use printk >>> delay and things like that. >>> I'm curious as to how kernel people debug PCs in general... >> >> We use a usb debug port connection (it's a special cable). For EHCI it is a special cable. For XHCI you can use a special cable but it is not required. (I saw a few people on LKML say that a normal data cable works so I tested it and it does work.) But if you want the special cable (for XHCI), this one works: https://www.datapro.net/products/usb-3-0-super-speed-a-a-debugging-cable.html So I tested with both the special debug cable and a normal A-A data cable, both with satisfactory results. > Sometimes people use netconsole (see > Documentation/networking/netconsole.rst). I don't know how common it is > nowadays, and it may not be quite as reliable as a debug port device, > but it should still work. And it doesn't require special hardware. It would be great if netconsole worked with wifi and not wired (ethernet). -- ~Randy
