On Mon, Jan 24, 2022 at 11:37:03PM +0100, Helge Deller wrote:
On 1/24/22 23:19, Daniel Vetter wrote:
On Mon, Jan 24, 2022 at 10:03:17PM +0100, Helge Deller wrote:
This series reverts two patches which disabled scrolling acceleration in fbcon/fbdev. Those patches introduced a regression for fbdev-supported graphic cards because of the performance penalty by doing screen scrolling by software instead of using existing 2D hardware acceleration.
This series has been discussed on linux-fbdev, dri-devel and linux-kernel mailing lists. The consensus is that they will be reverted, but in addition it's being worked on to find a solution which allows to disable parts of the classic fbdev hardware acceleration code which isn't needed in DRM-only configurations.
That's not my take at least.
Which is? Didn't we discussed about introducing something like CONFIG_FBCON_LEGACY_ACCELERATION ?
Yeah, as part of the reverts. Or at least that's what I meant to say. -Daniel
The patchset is planned to be kept in fbdev's for-next git branch and later pushed into kernel v5.18 if no issues are found until then.
Neither this. I don't think we've resovled maintainership of fbdev core code and fbcon yet. That is the part that drm folks very much still maintained, as a quick git shortlog will show.
Maintaining these parts outside of drm trees just doesn't make sense, since none of the other graphics relevant development happens outside of
I have no objections if you are willing to take those two patches through the drm tree.
Helge
Changes in v2 compared to v1:
- adjusted the stable tags (one v5.10+, the other v5.16+)
- moved the analysis and reasoning why those should be reverted into the commit message. That simplifies to analyze later why they were reverted.
- resorted the To an Cc mail recipient lists
Helge Deller (2): Revert "fbdev: Garbage collect fbdev scrolling acceleration, part 1 (from TODO list)" Revert "fbcon: Disable accelerated scrolling"
Documentation/gpu/todo.rst | 24 -- drivers/video/fbdev/core/bitblit.c | 16 + drivers/video/fbdev/core/fbcon.c | 540 +++++++++++++++++++++++- drivers/video/fbdev/core/fbcon.h | 59 +++ drivers/video/fbdev/core/fbcon_ccw.c | 28 +- drivers/video/fbdev/core/fbcon_cw.c | 28 +- drivers/video/fbdev/core/fbcon_rotate.h | 9 + drivers/video/fbdev/core/fbcon_ud.c | 37 +- drivers/video/fbdev/core/tileblit.c | 16 + drivers/video/fbdev/skeletonfb.c | 12 +- include/linux/fb.h | 2 +- 11 files changed, 703 insertions(+), 68 deletions(-)
-- 2.31.1