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  1. Qt
  2. QTBUG-41477

kms: hardcoded cursor size leading to artifacts

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    Details

    • Type: Bug
    • Status: Closed
    • Priority: P2: Important
    • Resolution: Done
    • Affects Version/s: 5.3.2
    • Fix Version/s: 5.4.0 Beta
    • Component/s: QPA: KMS
    • Labels:
      None

      Description

      In the constructor QKmsCursor::QKmsCursor() there is a call to gbm_bo_create with a hardcoded width/height of 64x64.

      We have a unit with a hardware cursor of 128x128. On this unit showing a Qt cursor leads to artifacts similar to: https://www.libreoffice.org/bugzilla/attachment.cgi?id=100690

      I don't know much about drm etc. but I have just followed the following change from an xorg driver:
      http://cgit.freedesktop.org/xorg/driver/xf86-video-modesetting/commit/?id=677935b2d20f54f21c645b5eb386b6c9485fee5f
      and came up with a patch to Qt (see attachment) which seems to solve the problem for us. For example with this patch at the above-mentioned unit the cursor size is automatically recognized as 128x128 and I see no artifacts, just the cursor (e.g. an arrow).

      In this patch I do the following:

      • if environment variables
        QT_CURSOR_WIDTH
        QT_CURSOR_HEIGHT
        are set, then these values are used for cursor size (so if something goes
        wrong with drmGetCap you can always set size manually);
      • if they are not set, then I call the drmGetCap() call to get settings and
        use these;
        (it's probably not needed: but as an extra protection: if I get from drmGetCap a value smaller than 32 then I use 32 instead
      • if QT_CURSOR_WIDTH/HEIGHT is not set, and drmGetCap() fails then default
        value of 64 (as hardcoded in current qt sources) is used

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            People

            Assignee:
            lagocs Laszlo Agocs
            Reporter:
            wiecko Marek Wieckowski
            Votes:
            1 Vote for this issue
            Watchers:
            3 Start watching this issue

              Dates

              Created:
              Updated:
              Resolved:

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