ARC: timer: rtc: implement read loop in "C" vs. inline asm (922cc171) · Commits · 戴 / test

The current code doesn't even compile as somehow the inline assembly can't see the register names defined as ARC_RTC_* I'm pretty sure It worked when I first got it merged, but the tools were definitely different then. So better to write this in "C" anyways. CC: stable@vger.kernel.org #4.2+ Acked-by:

Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by:

Vineet Gupta <vgupta@synopsys.com>

arch/arc/kernel/time.c

+11 −8

Original line number	Diff line number	Diff line
		@@ -152,14 +152,17 @@ static cycle_t arc_read_rtc(struct clocksource *cs)
		cycle_t full;
		} stamp;


		__asm__ __volatile(
		"1: \n"
		" lr %0, [AUX_RTC_LOW] \n"
		" lr %1, [AUX_RTC_HIGH] \n"
		" lr %2, [AUX_RTC_CTRL] \n"
		" bbit0.nt %2, 31, 1b \n"
		: "=r" (stamp.low), "=r" (stamp.high), "=r" (status));
		/*
		* hardware has an internal state machine which tracks readout of
		* low/high and updates the CTRL.status if
		* - interrupt/exception taken between the two reads
		* - high increments after low has been read
		*/
		do {
		stamp.low = read_aux_reg(AUX_RTC_LOW);
		stamp.high = read_aux_reg(AUX_RTC_HIGH);
		status = read_aux_reg(AUX_RTC_CTRL);
		} while (!(status & _BITUL(31)));

		return stamp.full;
		}

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