As discussed on irc, we rather improve the in-kernel DRM client's
support for cloned outputs (for fbcon) and then remove the hacks from
the ast and mgag200 drivers. Userspace compositors need to support
cloned outputs to a minimum.
https://dri.freedesktop.org/~cbrill/dri-log/index.php?channel=dri-devel&date=2024-07-17
Best regards
Thomas
Am 15.07.24 um 11:38 schrieb Thomas Zimmermann:
Old or simple hardware only supports a single CRTC with multiple
conenctoed outputs. This breaks most userspace compositors, which
only support a single output per CRTC. This currently happens with
ast and mgag200 drivers. The drivers contain a work around that
dynamically disables all but one connected output.
Patches 1 and 2 push the workaround into probe helpers and make it
configurable in the kernel config. For each connector, the driver
needs to specify a bitmask of connectors with higher priority. If
one of them is connected, the connector at hand is always reported
as disconnected. Connectors without priority bitmask as not affected.
Patches 3 to 5 update and simplify the ast drivers. The new workaround
now allows to have multiple physical conenctors in ast. So patch 5
finally allows VGA and DisplayPort on the same device.
Patches 6 and 7 update mgag200.
Any future driver that exposes the same problem as ast and mgag200
can simply hook into the workaround. Hopefully userspace can be fixed
at some point.
Thomas Zimmermann (7):
drm/probe-helper: Call connector detect functions in single helper
drm/probe-helper: Optionally report single connected output per CRTC
drm/ast: Set connector priorities
drm/ast: Remove struct ast_bmc_connector
drm/ast: Support ASTDP and VGA at the same time
drm/mgag200: Set connector priorities
drm/mgag200: Remove struct mgag200_bmc_connector
drivers/gpu/drm/Kconfig | 15 +++
drivers/gpu/drm/ast/ast_drv.h | 17 +--
drivers/gpu/drm/ast/ast_main.c | 2 +-
drivers/gpu/drm/ast/ast_mode.c | 49 ++------
drivers/gpu/drm/drm_probe_helper.c | 137 +++++++++++++++++++---
drivers/gpu/drm/mgag200/mgag200_bmc.c | 44 +------
drivers/gpu/drm/mgag200/mgag200_drv.h | 9 +-
drivers/gpu/drm/mgag200/mgag200_g200eh.c | 4 +-
drivers/gpu/drm/mgag200/mgag200_g200eh3.c | 4 +-
drivers/gpu/drm/mgag200/mgag200_g200er.c | 4 +-
drivers/gpu/drm/mgag200/mgag200_g200ev.c | 4 +-
drivers/gpu/drm/mgag200/mgag200_g200ew3.c | 4 +-
drivers/gpu/drm/mgag200/mgag200_g200se.c | 4 +-
drivers/gpu/drm/mgag200/mgag200_g200wb.c | 4 +-
include/drm/drm_connector.h | 2 +
include/drm/drm_probe_helper.h | 2 +
16 files changed, 177 insertions(+), 128 deletions(-)
--
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nuernberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman
HRB 36809 (AG Nuernberg)
