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[ Upstream commitb418d660bb] When commit:69c1f396f2("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. [ ardb: ensure efifb is unmapped again unless keep_bootcon is in effect. ] [ mingo: speling fixes. ] Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Cc: Arvind Sankar <nivedita@alum.mit.edu> Cc: Bhupesh Sharma <bhsharma@redhat.com> Cc: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com> Cc: linux-efi@vger.kernel.org Fixes:69c1f396f2("efi/x86: Convert x86 EFI earlyprintk into generic earlycon implementation") Link: https://lkml.kernel.org/r/20191206165542.31469-7-ardb@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>