no mouse cursor on nv50

[Ben Skeggs]

On Mon, Jun 18, 2018 at 7:46 AM, Adam Borowski <kilobyte at angband.pl> wrote:
> Hi!
> On v4.18-rc1, the mouse cursor is missing on my right monitor.
> Card is G98 [GeForce 8400 GS Rev. 2].
>
> I have two monitors: one small landscape 1280x1024 on DVI-I-1 left, and one
> big 1600x1200 (1200x1600 portrait) on HDMI-1 right.  Curiously, the cursor
> is missing not only with proper xrandr setup after logging in but even in
> mirrored mode at the lightdm greeter[1].  How is this even possible if both
> screens are supposed to be identical?
>
> Bisected:
> # bad: [ce397d215ccd07b8ae3f71db689aedb85d56ab40] Linux 4.18-rc1
> # good: [29dcea88779c856c7dc92040a0c01233263101d4] Linux 4.17
> git bisect start 'v4.18-rc1' 'v4.17'
> # bad: [1c8c5a9d38f607c0b6fd12c91cbe1a4418762a21] Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
> git bisect bad 1c8c5a9d38f607c0b6fd12c91cbe1a4418762a21
> # bad: [135c5504a600ff9b06e321694fbcac78a9530cd4] Merge tag 'drm-next-2018-06-06-1' of git://anongit.freedesktop.org/drm/drm
> git bisect bad 135c5504a600ff9b06e321694fbcac78a9530cd4
> # good: [5231804cf9e584f3e7e763a0d6d2fffe011c1bce] Merge tag 'leds_for_4.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/j.anaszewski/linux-leds
> git bisect good 5231804cf9e584f3e7e763a0d6d2fffe011c1bce
> # good: [315852b422972e6ebb1dfddaadada09e46a2681a] drm: rcar-du: Fix build failure
> git bisect good 315852b422972e6ebb1dfddaadada09e46a2681a
> # good: [ec064d3c6b40697fd72f4b1eeabbf293b7947a04] Merge tag 'driver-core-4.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
> git bisect good ec064d3c6b40697fd72f4b1eeabbf293b7947a04
> # bad: [ce234ccc03cfee004e168a1ae4b9d0cfb1974a32] Merge tag 'drm/tegra/for-4.18-rc1' of git://anongit.freedesktop.org/tegra/linux into drm-next
> git bisect bad ce234ccc03cfee004e168a1ae4b9d0cfb1974a32
> # bad: [d7c6e97a32329032ba7af1f53cab2767832fed77] drm/nouveau/kms/nv50-: modify base allocation so the code can be split
> git bisect bad d7c6e97a32329032ba7af1f53cab2767832fed77
> # good: [0a5b97304b9e2cd07c78a399c5395d5fb0118341] drm/nouveau/gr/gf100-: virtualise init_sked_hww_esr
> git bisect good 0a5b97304b9e2cd07c78a399c5395d5fb0118341
> # good: [18d17221dd58741a8590ba0a40a9ded82aa5d619] drm/nouveau/gr/gf100-: virtualise r419e00
> git bisect good 18d17221dd58741a8590ba0a40a9ded82aa5d619
> # good: [e9d03335f604a1123b8de3103ce8e06db4ad777a] drm/nouveau/gr/gp100-: use correct registers for zbc colour/depth setup
> git bisect good e9d03335f604a1123b8de3103ce8e06db4ad777a
> # good: [512fa0b8a398539c3c2db251f6c40da4ef065d09] drm/nouveau/drm/nv50-: remove allocation of sw class
> git bisect good 512fa0b8a398539c3c2db251f6c40da4ef065d09
> # good: [62b290fc7b36e8fec2a370b946d7117c1899b6c1] drm/nouveau/kms/nv50-: fix i2c-over-aux on anx9805
> git bisect good 62b290fc7b36e8fec2a370b946d7117c1899b6c1
> # bad: [a97c530eb968bad8d945d4f64fb550fa37a9d362] drm/nouveau/kms/nv50-: modify overlay allocation so the code can be split
> git bisect bad a97c530eb968bad8d945d4f64fb550fa37a9d362
> # bad: [5bca1621c07c3ad37b5a4943450a892e18984df0] drm/nouveau/kms/nv50-: move fb ctxdma tracking into windows
> git bisect bad 5bca1621c07c3ad37b5a4943450a892e18984df0
> # first bad commit: [5bca1621c07c3ad37b5a4943450a892e18984df0] drm/nouveau/kms/nv50-: move fb ctxdma tracking into windows
>
> Alas, the bad commit can't be easily reverted as there's a lot of further
> work on the file on question.

Thanks for the report!  Can you give
https://github.com/skeggsb/linux/commit/fffdc521f313031b1745a264ec0d5c848c2475d1
a try and see if it helps the issue you're seeing?

I'm presuming gnome must either render the cursor in sw, or at lease
have some kind of fallback, as multi-head cursors are working fine
here, which is why I didn't notice the issue earlier.

Ben.

>
> Meow!
>
> [1]. It's possible to setup lightdm for proper layout even on the login
> screen, but that gives only aesthetic bonus while possibly causing problems
> when the layout changes.
> --
> ⢀⣴⠾⠻⢶⣦⠀ There's an easy way to tell toy operating systems from real ones.
> ⣾⠁⢰⠒⠀⣿⡁ Just look at how their shipped fonts display U+1F52B, this makes
> ⢿⡄⠘⠷⠚⠋⠀ the intended audience obvious.  It's also interesting to see OSes
> ⠈⠳⣄⠀⠀⠀⠀ go back and forth wrt their intended target.