Hi Greg, Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> writes: > 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@xxxxxx> >> > Cc: stable@xxxxxxxxxxxxxxx # v5.16 >> >> Why just 5.16? This commit came in on 5.11 and was backported to >> 5.10.5. >> >> 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 > was a different revert and is still gone, thankfully :) > > 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. I'm counting more than 3 drivers using this. I think one of the reasons why it was reverted was that no one is actively maintaining fbdev. With Helge now volunteering i don't see a reason why it should stay reverted. If there are issues coming up i'm pretty sure Helge would care, and i would probably also take a look. /Sven
