On Thu, Jul 19, 2018 at 11:31:19PM +0200, Marcin Owsiany wrote: > Hello, > TL;DR: how can I set a 8960x2880 screen (not display) size on a T580? A > patch for i915 that I found on the internets does not seem to work. > Full story: > I'm a rather happy user of ThinkPad T580 which comes with a > high-density 3840x2160 LCD, and the following graphics hardware. > 00:02.0 VGA compatible controller: Intel Corporation Device 5917 (rev > 07) (prog-if 00 [VGA controller]) > Subsystem: Lenovo Device 225a > Flags: bus master, fast devsel, latency 0, IRQ 142 > Memory at e7000000 (64-bit, non-prefetchable) [size=16M] > Memory at c0000000 (64-bit, prefetchable) [size=256M] > I/O ports at e000 [size=64] > [virtual] Expansion ROM at 000c0000 [disabled] [size=128K] > Capabilities: [40] Vendor Specific Information: Len=0c <?> > Capabilities: [70] Express Root Complex Integrated Endpoint, > MSI 00 > Capabilities: [ac] MSI: Enable+ Count=1/1 Maskable- 64bit- > Capabilities: [d0] Power Management version 2 > Capabilities: [100] Process Address Space ID (PASID) > Capabilities: [200] Address Translation Service (ATS) > Capabilities: [300] Page Request Interface (PRI) > Kernel driver in use: i915 > Kernel modules: i915 > Unfortunately attaching it to an external normal-density 2560x1440 > display means I need to apply scaling. Combined with the side-by-side > arrangement of monitors, this means I'd need to set screen size > to 8960x2880. However this does not work: > $ xrandr --fb 8960x2880 > xrandr: screen cannot be larger than 8192x8192 (desired size > 8960x2880) > I found this [1]thread on reddit about the same problem, where a user > posted a simple patch claimed to be supplied by someone on #intel-gfx. > Unfortunately it does not work (or at least is not sufficient) - after > applying it xrandr does claim that 16384x16384 is possible, but > actually trying to use more than 8192x8192 fails with an error > (unfortunately I lost the exact message). I'm afraid that it is a hardware limitation that you won't be able to workaround. But a log would be interesting anyway... (both dmesg and xorg.0.log) > My current workaround is to pretend that the displays are arranged > vertically, but even after a few months I'm sometimes having trouble > remembering that I need to move mouse cursor UP when I want to go to > LEFT display :-) This is another bug.... And probably the right (only?) fixable fr your setup. > I wonder if someone could help me here. Even just getting a definite > answer on whether my hardware can in theory support this or not would > be helpful, since I found conflicting information. Well, I'm afraid the right information is already there on the first xrandr output. The rest was just misleading you. > FWIW I'm on Debian stable, Linux 4.9.8x. > regards, > Marcin > > References > > 1. https://www.reddit.com/r/linux/comments/6bghzm/increasing_maximum_xorg_virtual_screen_resolution/ > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@xxxxxxxxxxxxxxxxxxxxx > https://lists.freedesktop.org/mailman/listinfo/intel-gfx _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
