Re: i915 observations

[Frank Kardel <kardel%netbsd.org@localhost>]

Hi John !

I think you might be onto something there.
From Xorg.0.log (selected lines).
[    41.004] (--) PCI:*(0@0:2:0) 8086:9bc4:17aa:22a7 rev 5, Mem @ 
0x6040000000/16777216, 0x4000000000/268435456, I/O @ 0x00004000/64

Thats for the CPU
[    41.104] (II) intel: Driver for Intel(R) Integrated Graphics Chipsets:
        i810, i810-dc100, i810e, i815, i830M, 845G, 854, 852GM/855GM, 865G,
        915G, E7221 (i915), 915GM, 945G, 945GM, 945GME, Pineview GM,
        Pineview G, 965G, G35, 965Q, 946GZ, 965GM, 965GME/GLE, G33, 
Q35, Q33,
        GM45, 4 Series, G45/G43, Q45/Q43, G41, B43
[    41.105] (II) intel: Driver for Intel(R) HD Graphics
[    41.105] (II) intel: Driver for Intel(R) Iris(TM) Graphics
[    41.105] (II) intel: Driver for Intel(R) Iris(TM) Pro Graphics
[    41.105] (II) modesetting: Driver for Modesetting Kernel Drivers: kms
[    41.106] (II) VESA: driver for VESA chipsets: vesa
[    41.106] (II) wsfb: driver for wsdisplay framebuffer: wsfb
[    41.106] (--) Using wscons driver on /dev/ttyE4 in pcvt 
compatibility mode (version 3.32)
[    41.106] (--) using VT number 5
[    41.124] (II) intel(0): Using Kernel Mode Setting driver: i915, 
version 1.6.0 20200114
[    41.125] (WW) Falling back to old probe method for modesetting
[    41.126] (WW) Falling back to old probe method for wsfb
[    41.126] (WW) VGA arbiter: cannot open kernel arbiter, no multi-card 
support
### there is also an unsupported NVIDIA Card in there.
[    41.144] (II) intel(0): SNA initialized with disabled backend
[    41.144] (==) intel(0): Backing store enabled
[    41.144] (==) intel(0): Silken mouse enabled
[    41.147] (II) intel(0): HW Cursor enabled
[    41.153] (==) intel(0): DPMS enabled
[    41.157] (II) intel(0): Textured video not supported on this 
hardware or backend
[    41.157] (WW) intel(0): loading DRI2 whilst acceleration is disabled.

and yes SNA is enabled. I'll try with UXA tomorrow when I am back at the 
machine.

Thanks for the hint.

Frank

On 07/21/22 23:10, John D. Baker wrote:
> The description of the phenomena sounds a lot like what I observed when
> the intel driver from 2019 was imported and SNA acceleration (the default)
> was used on some older intel graphics devices.  Using the "modesetting"
> driver or setting UXA acceleration with the intel driver "fixed"
> (sidestepped?) the problem.  The default for the affected range of
> devices (as far as was known at the time) was later changed to UXA.
>
> What device(s) are used in the affected machines and are they trying to
> use SNA acceleration?