linux_dsm_epyc7002/arch
Thomas Gleixner 643d83f0a3 x86/hpet: Undo the early counter is counting check
Rui reported that on a Pentium D machine which has HPET forced enabled
because it is not advertised by ACPI, the early counter is counting check
leads to a silent boot hang.

The reason is that the ordering of checking the counter first and then
reconfiguring the HPET fails to work on that machine. As the HPET is not
advertised and presumably not initialized by the BIOS the early enable and
the following reconfiguration seems to bring it into a broken state. Adding
clocksource=jiffies to the command line results in the following
clocksource watchdog warning:

  clocksource: timekeeping watchdog on CPU1:
  Marking clocksource 'tsc-early' as unstable because the skew is too large:
  clocksource:  'hpet' wd_now: 33 wd_last: 33 mask: ffffffff

That clearly shows that the HPET is not counting after it got reconfigured
and reenabled. If the counter is not working then the HPET timer is not
expiring either, which explains the boot hang.

Move the counter is counting check after the full configuration again to
unbreak these systems.

Reported-by: Rui Salvaterra <rsalvaterra@gmail.com>
Fixes: 3222daf970 ("x86/hpet: Separate counter check out of clocksource register code")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Rui Salvaterra <rsalvaterra@gmail.com>
Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1907250810530.1791@nanos.tec.linutronix.de
2019-07-25 12:21:32 +02:00
..
alpha Merge branch 'akpm' (patches from Andrew) 2019-07-17 08:58:04 -07:00
arc Merge branch 'akpm' (patches from Andrew) 2019-07-17 08:58:04 -07:00
arm Kbuild updates for v5.3 (2nd) 2019-07-20 09:34:55 -07:00
arm64 Kbuild updates for v5.3 (2nd) 2019-07-20 09:34:55 -07:00
c6x Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu 2019-07-10 21:42:03 -07:00
csky arch/csky patches for 5.3-rc1 2019-07-19 12:15:33 -07:00
h8300 h8300 update for 5.3 2019-07-17 09:36:38 -07:00
hexagon hexagon: switch to generic version of pte allocation 2019-07-21 09:53:00 -07:00
ia64 Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-07-19 10:42:02 -07:00
m68k arch: mark syscall number 435 reserved for clone3 2019-07-15 00:39:33 +02:00
microblaze clone3-v5.3 2019-07-11 10:09:44 -07:00
mips This round of clk driver and framework updates is heavy on the driver update 2019-07-17 10:07:48 -07:00
nds32 nds32: fix asm/syscall.h 2019-07-16 19:23:24 -07:00
nios2 nios2 update for v5.3-rc1 2019-07-12 15:38:05 -07:00
openrisc dma-mapping updates for Linux 5.3 2019-07-12 15:13:55 -07:00
parisc Merge branch 'parisc-5.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux 2019-07-18 12:23:45 -07:00
powerpc mm/memory_hotplug: rename walk_memory_range() and pass start+size instead of pfns 2019-07-18 17:08:06 -07:00
riscv Kbuild updates for v5.3 (2nd) 2019-07-20 09:34:55 -07:00
s390 dma-mapping fixes for 5.3-rc1 2019-07-20 12:09:52 -07:00
sh mm/memory_hotplug: allow arch_remove_memory() without CONFIG_MEMORY_HOTREMOVE 2019-07-18 17:08:06 -07:00
sparc Kbuild updates for v5.3 (2nd) 2019-07-20 09:34:55 -07:00
um This pull request contains the following changes for UML: 2019-07-14 17:17:34 -07:00
unicore32 Kconfig updates for v5.3 2019-07-12 16:06:27 -07:00
x86 x86/hpet: Undo the early counter is counting check 2019-07-25 12:21:32 +02:00
xtensa Merge branch 'akpm' (patches from Andrew) 2019-07-17 08:58:04 -07:00
.gitignore
Kconfig Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-07-20 10:33:44 -07:00