Hello Greg,
On 1/19/22 12:47, Geert Uytterhoeven wrote:
On Wed, Jan 19, 2022 at 12:28 PM Greg Kroah-Hartman gregkh@linuxfoundation.org wrote:
On Wed, Jan 19, 2022 at 12:22:55PM +0100, Greg Kroah-Hartman wrote:
On Wed, Jan 19, 2022 at 12:08:39PM +0100, Helge Deller wrote:
This reverts commit 39aead8373b3c20bb5965c024dfb51a94e526151.
Revert this patch. This patch started to introduce the regression that all hardware acceleration of more than 35 existing fbdev drivers were bypassed and thus fbcon console output for those was dramatically slowed down by factor of 10 and more.
Reverting this commit has no impact on DRM, since none of the DRM drivers are tagged with the acceleration flags FBINFO_HWACCEL_COPYAREA, FBINFO_HWACCEL_FILLRECT or others.
Signed-off-by: Helge Deller deller@gmx.de
As for "why", I think there was a number of private bugs that were reported in this code, which is why it was removed. I do not think it can be safely added back in without addressing them first. Let me go dig through my email to see if I can find them...
Ah, no, that was just the soft scrollback code I was thinking of, which
Right. That was commit 973c096f6a85 and it was about vgacon, not fbcon.
I did mentioned it in my cover letter, together with my analysis of the reported bugs.
Maybe I should have put all the information from the cover letter into the patch here as well. If you haven't read the cover letter yet, please do.
Helge
So the bugs argument is moot.
was a different revert and is still gone, thankfully :)
FTR, not everyone else was thankful about that one...
This one was just removed because Daniel noticed that only 3 drivers used this (nouveau, omapdrm, and gma600), so this shouldn't have caused any regressions in any other drivers like you are reporting here.
So perhaps this regression is caused by something else?
- Daniel's patch was not CCed to linux-fbdev,
- When I discovered the patch, I pointed out that the premise of 3 drivers was not true, and that it affects 32 more fbdev drivers[1] . The patch was applied regardless.
- When the patch was suggested for backporting, I pointed out the same[2]. The patch was backported regardless.
[1] https://lore.kernel.org/r/alpine.DEB.2.22.394.2010311116530.379363@ramsan.of... [2] https://lore.kernel.org/r/CAMuHMdXRgam2zahPEGcw8+76Xm-0AO-Ci9-YmVa5JpTKVHphR...
Gr{oetje,eeting}s,
Geert