Hi Ben, Ben Hutchings <b...@decadent.org.uk> writes: > On Fri, 2017-07-14 at 20:34 +0200, Sascha Silbe wrote: >> Source: linux >> Version: 4.11.6-1 >> Severity: normal >> >> Dear Maintainer, >> >> on some amd64 systems no native or PCI(e) serial ports are available >> resp. possible. USB serial adapters are the only option to get a >> serial console for debugging boot problems in this case. Unfortunately >> the Debian amd64 kernels are built with USB_SERIAL_CONSOLE unset >> (because USB_SERIAL is not built-in) so even that option isn't >> available. When the BIOS text mode isn't working (e.g. high-res >> monitor with a BIOS that only supports up to FullHD) one is left >> without any working console device. > [...] > > I think this case is too unusual to make it worth building in all the > USB stuff needed to make this work on all x86 systems.
I’d like to respectfully ask you to reconsider this position. Over the years, more and more mainboards have dropped all support for any onboard serial ports. Using a USB serial console is nowadays often the only option for getting boot messages to another computer. I ran into this issue yesterday using an AsRock B550 Taichi mainboard, which has no serial headers. To make the USB console work, I had to build my own Debian kernel with the following options changed: CONFIG_USB=y CONFIG_USB_SERIAL=y CONFIG_USB_SERIAL_CONSOLE=y This is very tedious, partly because a build takes 42 minutes even on my latest-gen Ryzen CPU, and also because I don’t want to maintain a custom kernel build indefinitely. I don’t think this is a niche use case, at least not among users of serial consoles: other users of Debian and Ubuntu are running into this issue, too, see for example: https://unix.stackexchange.com/q/425280/181634 https://askubuntu.com/q/1269623 Notably, both Fedora and Arch Linux (the 2 other distributions I can quickly check) ship their default kernel with CONFIG_USB_SERIAL_CONSOLE=y: --- /tmp/config-debian 2021-07-27 23:29:22.648166910 +0200 +++ /tmp/config-fedora 2021-07-27 23:29:12.734958768 +0200 @@ -1,4 +1,5 @@ -CONFIG_USB_SERIAL=m +CONFIG_USB_SERIAL=y +CONFIG_USB_SERIAL_CONSOLE=y CONFIG_USB_SERIAL_GENERIC=y CONFIG_USB_SERIAL_SIMPLE=m CONFIG_USB_SERIAL_AIRCABLE=m @@ -16,7 +17,7 @@ So Debian seems like the odd one out. Given Debian’s popularity for server scenarios, I think we should make troubleshooting easier and have USB serial consoles just work. Could you please enable CONFIG_USB_SERIAL_CONSOLE=y? Thank you! -- Best regards, Michael
