[patch 12/29] x86/hpet: Simplify counter validation

From: Thomas Gleixner
Date: Sun Jun 23 2019 - 09:28:57 EST


There is no point to loop for 200k TSC cycles to check afterwards whether
the HPET counter is working. Read the counter inside of the loop and break
out when the counter value changed.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
arch/x86/kernel/hpet.c | 10 ++++------
1 file changed, 4 insertions(+), 6 deletions(-)

--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -853,15 +853,13 @@ static bool __init hpet_counting(void)
* 1 GHz == 200us
*/
do {
- rep_nop();
+ if (t1 != hpet_readl(HPET_COUNTER))
+ return true;
now = rdtsc();
} while ((now - start) < 200000UL);

- if (t1 == hpet_readl(HPET_COUNTER)) {
- pr_warn("Counter not counting. HPET disabled\n");
- return false;
- }
- return true;
+ pr_warn("Counter not counting. HPET disabled\n");
+ return false;
}

/**