[PATCH v2] tsc: Change default tsc calibration method to pmtimer on EFI systems

[PATCH v2] tsc: Change default tsc calibration method to pmtimer on EFI systems

[David E. Box]

On efi systems, make pmtimer based tsc calibration the default over the
pit. This prevents Grub from hanging on Intel SoC systems that power gate
the pit.

Signed-off-by: David E. Box <david.e.box@linux.intel.com>
---
ChangeLog:

v2: Make pmtimer the default. Keep the rest in the original order.

v1: Make efi timer the default followed by the pmtimer.

 grub-core/kern/i386/tsc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/grub-core/kern/i386/tsc.c b/grub-core/kern/i386/tsc.c
index 2e85289d8..5b9da7c86 100644
--- a/grub-core/kern/i386/tsc.c
+++ b/grub-core/kern/i386/tsc.c
@@ -68,7 +68,7 @@ grub_tsc_init (void)
 #ifdef GRUB_MACHINE_XEN
   (void) (grub_tsc_calibrate_from_xen () || calibrate_tsc_hardcode());
 #elif defined (GRUB_MACHINE_EFI)
-  (void) (grub_tsc_calibrate_from_pit () || grub_tsc_calibrate_from_pmtimer () || grub_tsc_calibrate_from_efi() || calibrate_tsc_hardcode());
+  (void) (grub_tsc_calibrate_from_pmtimer () || grub_tsc_calibrate_from_pit () || grub_tsc_calibrate_from_efi() || calibrate_tsc_hardcode());
 #elif defined (GRUB_MACHINE_COREBOOT)
   (void) (grub_tsc_calibrate_from_pmtimer () || grub_tsc_calibrate_from_pit () || calibrate_tsc_hardcode());
 #else
-- 
2.13.5

Re: [PATCH v2] tsc: Change default tsc calibration method to pmtimer on EFI systems

[Daniel Kiper]

On Fri, Sep 15, 2017 at 03:37:05PM -0700, David E. Box wrote:
> On efi systems, make pmtimer based tsc calibration the default over the
> pit. This prevents Grub from hanging on Intel SoC systems that power gate
> the pit.
>
> Signed-off-by: David E. Box <david.e.box@linux.intel.com>

LGTM. If there are no objections I will apply this next week.

Daniel

Re: [PATCH v2] tsc: Change default tsc calibration method to pmtimer on EFI systems

[Daniel Kiper]

On Thu, Sep 28, 2017 at 10:51:05PM +0200, Daniel Kiper wrote:
> On Fri, Sep 15, 2017 at 03:37:05PM -0700, David E. Box wrote:
> > On efi systems, make pmtimer based tsc calibration the default over the
> > pit. This prevents Grub from hanging on Intel SoC systems that power gate
> > the pit.
> >
> > Signed-off-by: David E. Box <david.e.box@linux.intel.com>
>
> LGTM. If there are no objections I will apply this next week.

Committed!

Thanks,

Daniel