linux_dsm_epyc7002/arch
Thomas Gleixner 979923871f x86/timer: Don't skip PIT setup when APIC is disabled or in legacy mode
Tony reported a boot regression caused by the recent workaround for systems
which have a disabled (clock gate off) PIT.

On his machine the kernel fails to initialize the PIT because
apic_needs_pit() does not take into account whether the local APIC
interrupt delivery mode will actually allow to setup and use the local
APIC timer. This should be easy to reproduce with acpi=off on the
command line which also disables HPET.

Due to the way the PIT/HPET and APIC setup ordering works (APIC setup can
require working PIT/HPET) the information is not available at the point
where apic_needs_pit() makes this decision.

To address this, split out the interrupt mode selection from
apic_intr_mode_init(), invoke the selection before making the decision
whether PIT is required or not, and add the missing checks into
apic_needs_pit().

Fixes: c8c4076723 ("x86/timer: Skip PIT initialization on modern chipsets")
Reported-by: Anthony Buckley <tony.buckley000@gmail.com>
Tested-by: Anthony Buckley <tony.buckley000@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Daniel Drake <drake@endlessm.com>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=206125
Link: https://lore.kernel.org/r/87sgk6tmk2.fsf@nanos.tec.linutronix.de
2020-01-29 12:50:12 +01:00
..
alpha alpha: use pgtable-nopud instead of 4level-fixup 2019-12-04 19:44:14 -08:00
arc ARC fixes for v5.5-rc6 2020-01-06 10:16:48 -08:00
arm ARM: SoC fixes 2020-01-16 19:42:08 -08:00
arm64 ARM: SoC fixes 2020-01-16 19:42:08 -08:00
c6x c6x: use pgtable-nopud instead of 4level-fixup 2019-12-04 19:44:15 -08:00
csky dma-mapping updates for 5.5-rc1 2019-11-28 11:16:43 -08:00
h8300 h8300: Move EXCEPTION_TABLE to RO_DATA segment 2019-11-04 18:12:55 +01:00
hexagon hexagon: define ioremap_uc 2020-01-04 13:55:09 -08:00
ia64 mm/memory_hotplug: shrink zones when offlining memory 2020-01-04 13:55:08 -08:00
m68k Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu 2019-12-05 12:20:42 -08:00
microblaze microblaze: use pgtable-nopmd instead of 4level-fixup 2019-12-04 19:44:15 -08:00
mips A collection of MIPS fixes: 2020-01-04 14:16:57 -08:00
nds32 nds32: fix build failure caused by page table folding updates 2019-12-30 11:19:05 +01:00
nios2 nios2: Fix ioremap 2019-12-12 16:34:33 +08:00
openrisc OpenRISC updates for 5.5 2019-12-02 17:18:43 -08:00
parisc Merge branch 'parisc-5.5-3' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux 2020-01-14 10:22:10 -08:00
powerpc mm/memory_hotplug: shrink zones when offlining memory 2020-01-04 13:55:08 -08:00
riscv riscv: Less inefficient gcc tishift helpers (and export their symbols) 2020-01-18 19:13:41 -08:00
s390 s390/setup: Fix secure ipl message 2020-01-09 16:59:18 +01:00
sh mm/memory_hotplug: shrink zones when offlining memory 2020-01-04 13:55:08 -08:00
sparc treewide: Use sizeof_field() macro 2019-12-09 10:36:44 -08:00
um um: Implement copy_thread_tls 2020-01-07 13:31:29 +01:00
unicore32 generic ioremap support 2019-11-28 10:57:12 -08:00
x86 x86/timer: Don't skip PIT setup when APIC is disabled or in legacy mode 2020-01-29 12:50:12 +01:00
xtensa xtensa: Implement copy_thread_tls 2020-01-07 13:31:25 +01:00
.gitignore
Kconfig arch/Kconfig: fix indentation 2019-12-04 19:44:12 -08:00