[RFC PATCH v2 0/5] VT: Add ability to get font requirements

[Alexey Gladkov <legion@kernel.org>]

We now have KD_FONT_OP_SET_TALL, but in fact such large fonts cannot be
loaded. No console driver supports tall fonts. Unfortunately, userspace
cannot distinguish the lack of support in the driver from errors in the
font itself. In all cases, EINVAL will be returned.

In order not to hack the KDFONTOP interface, I suggest adding a new ioctl to
obtain information about the capabilities of the console driver.

This is the second version of the patch with the fixes pointed out by Jiri
Slaby.

Previous version: https://lore.kernel.org/all/cover.1708011391.git.legion@kernel.org/

---

Alexey Gladkov (5):
  VT: Add KD_FONT_OP_GET_INFO operation
  newport_con: Allow to get max font width and height
  sticon: Allow to get max font width and height
  vgacon: Allow to get max font width and height
  fbcon: Allow to get max font width and height

 drivers/tty/vt/vt.c                 | 24 ++++++++++++++++++++++++
 drivers/tty/vt/vt_ioctl.c           | 12 ++++++++++++
 drivers/video/console/newport_con.c | 21 +++++++++++++++++----
 drivers/video/console/sticon.c      | 25 +++++++++++++++++++++++--
 drivers/video/console/vgacon.c      | 21 ++++++++++++++++++++-
 drivers/video/fbdev/core/fbcon.c    | 22 +++++++++++++++++++++-
 include/linux/console.h             |  2 ++
 include/linux/vt_kern.h             |  1 +
 include/uapi/linux/kd.h             | 13 ++++++++++++-
 9 files changed, 132 insertions(+), 9 deletions(-)

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2.44.0