DM composed on 2025-06-12 10:58 (UTC+0200): > schrieb Felix Miata:
>> DM composed on 2025-06-09 15:03 (UTC+0200): >>> (I couldn't get Debian Trixie to start wayland session when setting >>> "nomodeset", only X11 session) >>> And in this situation: i.e. Fedora, Kernel 6.14, Wayland, I could rotate >>> the internal screen. >>> So when I have more time again, I will again install Fedora and probably >>> use that for now. Only 800x600 instead of the full 1280x800 display >>> resolution, but on 8°, that's good enough for now. >> In fallback modes, such as when using nomodeset, modes are normally limited >> to standard VESA modes, all of which are 4:3 modes, with possible exception >> of 1920x1080 with some hardware, and none of which (IIRC) are portrait. >> 1280x800 is 16:10, not among traditional VESA's standard repertoire. > Unfortunately, my day job keeps me away from the laptop (both in space and > time) for the next couple of weeks. But I will try to experiment with > specifying different VESA modes at boot. Am I correct in thinking that I > would > need something like "VGA=1024x768" or similar in my linux cmd line? In conjunction with disabling KMS, vga= traditionally will determine mode used in vtty 1-6 consoles. VESA modes can be found in lookup tables such as at: <https://en.wikipedia.org/wiki/VESA_BIOS_Extensions#Linux_video_mode_numbers> e.g. for 16bit 1024x768 use either vga=791 or vga=0x314, and 24bit either vga=792 or vga=0x318. When KMS is not disabled, vga can work only for the period between loaded initrd and KMS engagement. Subsequently, video= is all that can be engaged. With two different displays, an example would be simply video=1440x900 to have both displays running it, or video=eDP-1:1280x800@60e video=HDMI-A-1:1920x1080@60e to have a laptop run 1280x800 on its internal display, and 1920x1080 on an HDMI connected TV. In this latter case, on the vttys, the TV would run in 1920x1080 mode, but output would be expected to be limited to the upper left corner's 1024x768 framebuffer. With limited function X in effect, these mode specifications may or may not remain effective. When they do, then full use of each screen can normally be expected. See: <https://www.kernel.org/doc/Documentation/fb/modedb.txt> >>>> Nomodeset is a troubleshooting workaround that never supports two displays. >> Somewhere in your thread I thought I saw mention use of nomodeset in >> conjunction with seeing both displays lit at once running Linux. I've never >> been able to make that happen with any distro or kernel on upwards of at >> least 50 computers. > I did have both screens available - but not as independent displays, only as > mirror of each other. > It definitely worked in Fedora 42 in safe graphics mode, and also in some > Debian varieties when using "nomodeset", but I am not sure any more, which > ones (i.e. which kernel). Some BIOS/UEFI firmware when allowed to retain some effect will support lighting both displays, but only in mirrored mode. ... -- Evolution as taught in public schools is, like religion, based on faith, not based on science. Team OS/2 ** Reg. Linux User #211409 ** a11y rocks! Felix Miata
