diff options
| author | Feng Tang <[email protected]> | 2015-06-15 17:40:01 +0800 |
|---|---|---|
| committer | Ingo Molnar <[email protected]> | 2015-06-18 10:57:38 +0200 |
| commit | b58d930750135d6c5b8e5aa084c0e9303c78c286 (patch) | |
| tree | fd7aacf41b5fbc6e6d3c7ffae910aa2322450a9c | |
| parent | 956079e081427fe0c929eb284ab7e39f9b8e2023 (diff) | |
x86/platform/intel/baytrail: Add comments about why we disabled HPET on Baytrail
This question has been asked many times, and finally I found the
official document which explains the problem of HPET on Baytrail,
that it will halt in deep idle states.
Signed-off-by: Feng Tang <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Brian Gerst <[email protected]>
Cc: Denys Vlasenko <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]
[ Prettified things a bit. ]
Signed-off-by: Ingo Molnar <[email protected]>
| -rw-r--r-- | arch/x86/kernel/early-quirks.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/arch/x86/kernel/early-quirks.c b/arch/x86/kernel/early-quirks.c index fe9f0b79a18b..5cb9a4d6f623 100644 --- a/arch/x86/kernel/early-quirks.c +++ b/arch/x86/kernel/early-quirks.c @@ -627,8 +627,12 @@ static struct chipset early_qrk[] __initdata = { { PCI_VENDOR_ID_INTEL, PCI_ANY_ID, PCI_CLASS_DISPLAY_VGA, PCI_ANY_ID, QFLAG_APPLY_ONCE, intel_graphics_stolen }, /* - * HPET on current version of Baytrail platform has accuracy - * problems, disable it for now: + * HPET on the current version of the Baytrail platform has accuracy + * problems: it will halt in deep idle state - so we disable it. + * + * More details can be found in section 18.10.1.3 of the datasheet: + * + * http://www.intel.com/content/dam/www/public/us/en/documents/datasheets/atom-z8000-datasheet-vol-1.pdf */ { PCI_VENDOR_ID_INTEL, 0x0f00, PCI_CLASS_BRIDGE_HOST, PCI_ANY_ID, 0, force_disable_hpet}, |