Bug 391412

Summary: bool DrmOutput::initCursorPlane is not hooked with anything else
Product: [Plasma] kwin Reporter: Bhushan Shah <bshah>
Component: platform-drmAssignee: KWin default assignee <kwin-bugs-null>
Status: RESOLVED NOT A BUG    
Severity: normal CC: simonandric5
Priority: NOR    
Version First Reported In: 5.12.1   
Target Milestone: ---   
Platform: Other   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:

Description Bhushan Shah 2018-03-05 06:12:56 UTC 
Assumption that, if there is cursor plane  provided by the DRM driver, mouse will work with using cursor plane is never satisfied.

https://cgit.kde.org/kwin.git/tree/plugins/platforms/drm/drm_output.cpp#n645 is never hooked with anything else.
Comment 1 Martin Flöser 2018-03-05 16:21:21 UTC 
KWin doesn't use the cursor plane to draw the cursor. Instead it uses the high level api provided by DRM to draw the cursor.
Comment 2 Bhushan Shah 2018-03-05 16:26:21 UTC 
Ah.. Sorry for wrong assumption.

It is related to the https://mail.kde.org/pipermail/plasma-devel/2018-March/082150.html

I wanted to investigate why it doesn't seem to fallback to software cursor correctly.
Comment 3 Bhushan Shah 2018-03-05 16:28:40 UTC 
and perhaps the code pointed above in comment #0 should be removed to avoid confusion? :)
Comment 4 Martin Flöser 2018-03-05 17:48:27 UTC 
(In reply to Bhushan Shah from comment #2)
> Ah.. Sorry for wrong assumption.
> 
> It is related to the
> https://mail.kde.org/pipermail/plasma-devel/2018-March/082150.html
> 
> I wanted to investigate why it doesn't seem to fallback to software cursor
> correctly.

Afaik there is no fallback in the DRM platform.
Comment 5 Bhushan Shah 2018-03-05 18:11:50 UTC 
Ah, so https://phabricator.kde.org/D6186 doesn't implement fallback? The hardware in question doesn't report hardware plane, but it doesn't use software cursor also..
Comment 6 Bhushan Shah 2018-03-05 18:17:16 UTC 
kwin_wayland log


kwin_core: Session path: "/org/freedesktop/login1/session/_322"
kwin_core: "logind"  seat: "seat0" / "/org/freedesktop/login1/seat/seat0"
kwin_core: "logind"  seat: "seat0" / "/org/freedesktop/login1/seat/seat0"
kwin_core: Gained session control
kwin_libinput: Libinput: event0  - gpio-keys: is tagged by udev as: Keyboard

kwin_libinput: Libinput: event0  - gpio-keys: device is a keyboard

kwin_libinput: Libinput: event1  - VISENTA V1 : is tagged by udev as: Keyboard

kwin_libinput: Libinput: event1  - VISENTA V1 : device is a keyboard

kwin_libinput: Libinput: event2  - VISENTA V1 : is tagged by udev as: Keyboard Mouse

kwin_libinput: Libinput: event2  - VISENTA V1 : device is a pointer

kwin_libinput: Libinput: event2  - VISENTA V1 : device is a keyboard

kwin_wayland_drm: Using Atomic Mode Setting.
kwin_wayland_drm: Number of planes: 6
kwin_wayland_drm: Atomic init for plane: 28
kwin_wayland_drm: 28: type' (id 7): 1
kwin_wayland_drm: "type"  has enums: QVector("Primary", "Cursor", "Overlay")
kwin_wayland_drm: Test all 3 possible enums:
kwin_wayland_drm: Enum 'Overlay': runtime-value = 0
kwin_wayland_drm: Enum 'Primary': runtime-value = 1
kwin_wayland_drm: Enum 'Cursor': runtime-value = 2
kwin_wayland_drm: => "type" with mapped enum value "Primary"
kwin_wayland_drm: 28: SRC_X' (id 8): 0
kwin_wayland_drm: 28: SRC_Y' (id 9): 0
kwin_wayland_drm: 28: SRC_W' (id 10): 70778880
kwin_wayland_drm: 28: SRC_H' (id 11): 125829120
kwin_wayland_drm: 28: CRTC_X' (id 12): 0
kwin_wayland_drm: 28: CRTC_Y' (id 13): 0
kwin_wayland_drm: 28: CRTC_W' (id 14): 1080
kwin_wayland_drm: 28: CRTC_H' (id 15): 1920
kwin_wayland_drm: 28: FB_ID' (id 16): 43
kwin_wayland_drm: 28: CRTC_ID' (id 19): 29
kwin_wayland_drm: Supported Transformations:  QFlags()  on plane  28
kwin_wayland_drm: Atomic init for plane: 30
kwin_wayland_drm: 30: type' (id 7): 0
kwin_wayland_drm: "type"  has enums: QVector("Primary", "Cursor", "Overlay")
kwin_wayland_drm: Test all 3 possible enums:
kwin_wayland_drm: Enum 'Overlay': runtime-value = 0
kwin_wayland_drm: Enum 'Primary': runtime-value = 1
kwin_wayland_drm: Enum 'Cursor': runtime-value = 2
kwin_wayland_drm: => "type" with mapped enum value "Overlay"
kwin_wayland_drm: 30: SRC_X' (id 8): 0
kwin_wayland_drm: 30: SRC_Y' (id 9): 0
kwin_wayland_drm: 30: SRC_W' (id 10): 0
kwin_wayland_drm: 30: SRC_H' (id 11): 0
kwin_wayland_drm: 30: CRTC_X' (id 12): 0
kwin_wayland_drm: 30: CRTC_Y' (id 13): 0
kwin_wayland_drm: 30: CRTC_W' (id 14): 0
kwin_wayland_drm: 30: CRTC_H' (id 15): 0
kwin_wayland_drm: 30: FB_ID' (id 16): 0
kwin_wayland_drm: 30: CRTC_ID' (id 19): 0
kwin_wayland_drm: Supported Transformations:  QFlags()  on plane  30
kwin_wayland_drm: Atomic init for plane: 31
kwin_wayland_drm: 31: type' (id 7): 1
kwin_wayland_drm: "type"  has enums: QVector("Primary", "Cursor", "Overlay")
kwin_wayland_drm: Test all 3 possible enums:
kwin_wayland_drm: Enum 'Overlay': runtime-value = 0
kwin_wayland_drm: Enum 'Primary': runtime-value = 1
kwin_wayland_drm: Enum 'Cursor': runtime-value = 2
kwin_wayland_drm: => "type" with mapped enum value "Primary"
kwin_wayland_drm: 31: SRC_X' (id 8): 0
kwin_wayland_drm: 31: SRC_Y' (id 9): 0
kwin_wayland_drm: 31: SRC_W' (id 10): 0
kwin_wayland_drm: 31: SRC_H' (id 11): 0
kwin_wayland_drm: 31: CRTC_X' (id 12): 0
kwin_wayland_drm: 31: CRTC_Y' (id 13): 0
kwin_wayland_drm: 31: CRTC_W' (id 14): 0
kwin_wayland_drm: 31: CRTC_H' (id 15): 0
kwin_wayland_drm: 31: FB_ID' (id 16): 0
kwin_wayland_drm: 31: CRTC_ID' (id 19): 0
kwin_wayland_drm: Supported Transformations:  QFlags()  on plane  31
kwin_wayland_drm: Atomic init for plane: 33
kwin_wayland_drm: 33: type' (id 7): 1
kwin_wayland_drm: "type"  has enums: QVector("Primary", "Cursor", "Overlay")
kwin_wayland_drm: Test all 3 possible enums:
kwin_wayland_drm: Enum 'Overlay': runtime-value = 0
kwin_wayland_drm: Enum 'Primary': runtime-value = 1
kwin_wayland_drm: Enum 'Cursor': runtime-value = 2
kwin_wayland_drm: => "type" with mapped enum value "Primary"
kwin_wayland_drm: 33: SRC_X' (id 8): 0
kwin_wayland_drm: 33: SRC_Y' (id 9): 0
kwin_wayland_drm: 33: SRC_W' (id 10): 0
kwin_wayland_drm: 33: SRC_H' (id 11): 0
kwin_wayland_drm: 33: CRTC_X' (id 12): 0
kwin_wayland_drm: 33: CRTC_Y' (id 13): 0
kwin_wayland_drm: 33: CRTC_W' (id 14): 0
kwin_wayland_drm: 33: CRTC_H' (id 15): 0
kwin_wayland_drm: 33: FB_ID' (id 16): 0
kwin_wayland_drm: 33: CRTC_ID' (id 19): 0
kwin_wayland_drm: Supported Transformations:  QFlags()  on plane  33
kwin_wayland_drm: Atomic init for plane: 35
kwin_wayland_drm: 35: type' (id 7): 0
kwin_wayland_drm: "type"  has enums: QVector("Primary", "Cursor", "Overlay")
kwin_wayland_drm: Test all 3 possible enums:
kwin_wayland_drm: Enum 'Overlay': runtime-value = 0
kwin_wayland_drm: Enum 'Primary': runtime-value = 1
kwin_wayland_drm: Enum 'Cursor': runtime-value = 2
kwin_wayland_drm: => "type" with mapped enum value "Overlay"
kwin_wayland_drm: 35: SRC_X' (id 8): 0
kwin_wayland_drm: 35: SRC_Y' (id 9): 0
kwin_wayland_drm: 35: SRC_W' (id 10): 0
kwin_wayland_drm: 35: SRC_H' (id 11): 0
kwin_wayland_drm: 35: CRTC_X' (id 12): 0
kwin_wayland_drm: 35: CRTC_Y' (id 13): 0
kwin_wayland_drm: 35: CRTC_W' (id 14): 0
kwin_wayland_drm: 35: CRTC_H' (id 15): 0
kwin_wayland_drm: 35: FB_ID' (id 16): 0
kwin_wayland_drm: 35: CRTC_ID' (id 19): 0
kwin_wayland_drm: Supported Transformations:  QFlags()  on plane  35
kwin_wayland_drm: Atomic init for plane: 36
kwin_wayland_drm: 36: type' (id 7): 1
kwin_wayland_drm: "type"  has enums: QVector("Primary", "Cursor", "Overlay")
kwin_wayland_drm: Test all 3 possible enums:
kwin_wayland_drm: Enum 'Overlay': runtime-value = 0
kwin_wayland_drm: Enum 'Primary': runtime-value = 1
kwin_wayland_drm: Enum 'Cursor': runtime-value = 2
kwin_wayland_drm: => "type" with mapped enum value "Primary"
kwin_wayland_drm: 36: SRC_X' (id 8): 0
kwin_wayland_drm: 36: SRC_Y' (id 9): 0
kwin_wayland_drm: 36: SRC_W' (id 10): 0
kwin_wayland_drm: 36: SRC_H' (id 11): 0
kwin_wayland_drm: 36: CRTC_X' (id 12): 0
kwin_wayland_drm: 36: CRTC_Y' (id 13): 0
kwin_wayland_drm: 36: CRTC_W' (id 14): 0
kwin_wayland_drm: 36: CRTC_H' (id 15): 0
kwin_wayland_drm: 36: FB_ID' (id 16): 0
kwin_wayland_drm: 36: CRTC_ID' (id 19): 0
kwin_wayland_drm: Supported Transformations:  QFlags()  on plane  36
kwin_wayland_drm: Creating connector 39
kwin_wayland_drm: 39: CRTC_ID' (id 19): 29
kwin_wayland_drm: Atomic init for CRTC: 0 id: 29
kwin_wayland_drm: 29: MODE_ID' (id 21): 55
kwin_wayland_drm: 29: ACTIVE' (id 20): 1
kwin_wayland_drm: Atomic init for CRTC: 1 id: 32
kwin_wayland_drm: 32: MODE_ID' (id 21): 0
kwin_wayland_drm: 32: ACTIVE' (id 20): 0
kwin_wayland_drm: Atomic init for CRTC: 2 id: 34
kwin_wayland_drm: 34: MODE_ID' (id 21): 0
kwin_wayland_drm: 34: ACTIVE' (id 20): 0
kwin_wayland_drm: Atomic init for CRTC: 3 id: 37
kwin_wayland_drm: 37: MODE_ID' (id 21): 0
kwin_wayland_drm: 37: ACTIVE' (id 20): 0
kwin_wayland_drm: For new output use mode  1080x1920
kwin_wayland_drm: Initialized primary plane 28 on CRTC 29
kwin_wayland_drm: Adding mode:  0 QSize(1080, 1920)
kwin_wayland_drm: New DPMS mode equals old mode. DPMS unchanged.
kwin_wayland_drm: Found new output with uuid "c43729dd27"
kwin_wayland_drm: Reading output configuration for [ "c43729dd27" ] [ "c43729dd27" ]
Comment 7 Martin Flöser 2018-03-05 20:23:05 UTC 
(In reply to Bhushan Shah from comment #5)
> Ah, so https://phabricator.kde.org/D6186 doesn't implement fallback? The
> hardware in question doesn't report hardware plane, but it doesn't use
> software cursor also..

No, it doesn't have any checks whether the DRM driver supports cursor. KWin just uses drmModeSetCursor - there is no check whether the driver supports that and no fallback to anything else. If drm is used, it is assumed that the driver supports that.
Comment 8 Martin Flöser 2018-03-05 20:38:21 UTC 
I need to slightly correct myself: if the initial mapping of a cursor fails, software rendering is enabled, see drm_backend.cpp:464