lkml.org 
[lkml]   [2018]   [Feb]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: Thinkpad X1 Carbon 3rd - Reducing the compressed framebuffer size
    On Tue, Feb 13, 2018 at 06:43:41PM +0100, Pali Rohár wrote:
    > On Tuesday 13 February 2018 18:12:21 Ville Syrjälä wrote:
    > > On Tue, Feb 13, 2018 at 05:04:37PM +0100, Pali Rohár wrote:
    > > > $ cat /sys/kernel/debug/dri/0/i915_gem_stolen
    > > > Stolen:
    > > > ffff8b55bf17e080: g 16KiB 40 40 [ 0 0 0 0 ] 0 LLC dirty (pinned x 1) (ggtt offset: 00083000, size: 00004000, type: 0) (stolen: 00001000)
    > > > ffff8b55c2693040: g 16KiB 40 40 [ 0 0 0 0 ] 0 LLC dirty (pinned x 1) (ggtt offset: 02b9f000, size: 00004000, type: 0) (stolen: 00005000)
    > > > ffff8b55bf9a7300: g 16KiB 40 40 [ 0 0 0 0 ] 0 LLC dirty (pinned x 0) (ggtt offset: 0f6b4000, size: 00004000, type: 0) (stolen: 00009000)
    > > > ffff8b55a6161040: g 16KiB 40 40 [ 0 0 0 0 ] 0 LLC dirty (pinned x 0) (ggtt offset: 0937f000, size: 00004000, type: 0) (stolen: 0000d000)
    > > > ffff8b5563e0dac0: g 16KiB 40 40 [ 0 0 0 0 ] 0 LLC dirty (pinned x 0) (ggtt offset: 0f714000, size: 00004000, type: 0) (stolen: 00019000)
    > > > ffff8b55bf17e800: g 4KiB 41 00 [ 0 0 0 0 ] 0 LLC (pinned x 1) (ggtt offset: ffffe000, size: 00001000, type: 0) (stolen: 0012c000)
    > > > ffff8b55bf02d540: g 16KiB 40 40 [ 0 0 0 0 ] 0 LLC dirty (pinned x 1) (ggtt offset: 00141000, size: 00004000, type: 0) (stolen: 0012d000)
    > > > ffff8b55c2989340: g 16KiB 40 40 [ 0 0 0 0 ] 0 LLC dirty (pinned x 1) (ggtt offset: 00148000, size: 00004000, type: 0) (stolen: 00131000)
    > > > ffff8b55c29890c0: g 16KiB 40 40 [ 0 0 0 0 ] 0 LLC dirty (pinned x 1) (ggtt offset: 0014f000, size: 00004000, type: 0) (stolen: 00135000)
    > > > ffff8b55c2989840: g 16KiB 40 40 [ 0 0 0 0 ] 0 LLC dirty (pinned x 1) (ggtt offset: 00156000, size: 00004000, type: 0) (stolen: 00139000)
    > > > ffff8b55bf02da40: p g 14400KiB 77 00 [ 0 0 0 0 ] 0 uncached dirty (name: 1) (pinned x 1) (display) (ggtt offset: 0015a000, size: 00e10000, type: 0) (stolen: 0013d000) (p mappable)
    > > > ffff8b556dfba780: g 16KiB 40 40 [ 0 0 0 0 ] 0 LLC dirty (pinned x 0) (ggtt offset: 0ad2a000, size: 00004000, type: 0) (stolen: 01655000)
    > > >
    > > > > likely you'll have the fbdev framebuffer taking up a sizeable chunk.
    > > >
    > > > Seems 14MB.
    > > >
    > > > > You could get some back by reducing fbdev depth to 16bpp, or even 8bpp,
    > > > > but I'm not convinced the fbdev gamma LUT stuff really works currently
    > > > > so you might end up with bogus colors in your vts with that.
    > > >
    > > > Ok, I could try it. Via fbset tool?
    > >
    > > Kernel command line. We don't allow resizing the fbdev fb once it's
    > > created.
    >
    > Ok, will try.
    >
    > > >
    > > > > >
    > > > > > [ 0.000000] Memory: 7972840K/8282704K available (6196K kernel code, 1159K rwdata, 2848K rodata, 1408K init, 688K bss, 309864K reserved, 0K cma-reserved)
    > > > > >
    > > > > > > The BIOS may or may not provide a knob to change the size
    > > > > > > of the stolen memory.
    > > > > >
    > > > > > In BIOS Setup screen I have option to choose GPU memory and I set it to
    > > > > > max 512MB. So this is not the right option...
    > > > > >
    > > > > > And why cannot kernel use some continuous check of RAM itself?
    > > > >
    > > > > Because the hardware won't allow it.
    > > >
    > > > So it can be done only once after reboot? Or only prior to booting kernel?
    > >
    > > Never.
    >
    > Never? Now I'm lost. Why then dmesg message instruct user to try set up
    > it in BIOS if you say it is never possible?

    You can change it in the BIOS. No way to change it from the operating system.

    --
    Ville Syrjälä
    Intel OTC

    \
     
     \ /
      Last update: 2018-02-13 18:46    [W:3.112 / U:0.716 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site