On Fri, Dec 06, 2019 at 04:55:42PM +0000, Ard Biesheuvel wrote: > From: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> > > When commit 69c1f396f25b > > "efi/x86: Convert x86 EFI earlyprintk into generic earlycon implementation" > > moved the x86 specific EFI earlyprintk implementation to a shared location, > it also tweaked the behaviour. In particular, it dropped a trick with full > framebuffer remapping after page initialization, leading to two regressions: > 1) very slow scrolling after page initialization, > 2) kernel hang when the 'keep_bootcon' command line argument is passed. > > Putting the tweak back fixes #2 and mitigates #1, i.e., it limits the slow > behavior to the early boot stages, presumably due to eliminating heavy > map()/unmap() operations per each pixel line on the screen. > Could the efi earlycon have an interaction with PCI resource allocation, similar to what commit dcf8f5ce3165 ("drivers/fbdev/efifb: Allow BAR to be moved instead of claiming it") fixed for efifb?