Commit 44b5be57 authored Jun 23, 2019 by Thomas Gleixner

x86/hpet: Simplify counter validation



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@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
Cc: Ashok Raj <ashok.raj@intel.com>
Cc: Andi Kleen <andi.kleen@intel.com>
Cc: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Ravi Shankar <ravi.v.shankar@intel.com>
Link: https://lkml.kernel.org/r/20190623132435.149535103@linutronix.de

parent 3222daf9

arch/x86/kernel/hpet.c

+4 −6

Original line number	Diff line number	Diff line
		@@ -853,16 +853,14 @@ 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;
		}

		/**
		* hpet_enable - Try to setup the HPET timer. Returns 1 on success.

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