Hi Vineet, > -----Original Message----- > From: Vineet Gupta [mailto:vgu...@synopsys.com] > Sent: Friday, November 04, 2016 12:32 AM > To: Daniel Lezcano <daniel.lezc...@linaro.org> > Cc: Noam Camus <noa...@mellanox.com>; t...@linutronix.de; > linux-snps-arc@lists.infradead.org; linux-ker...@vger.kernel.org; > alexey.brod...@synopsys.com; Vineet Gupta <vgu...@synopsys.com>; > sta...@vger.kernel.org > Subject: [PATCH v2 01/10] ARC: timer: rtc: implement read loop in "C" vs. > inline asm > > The current code doesn't even compile .... > > CC: sta...@vger.kernel.org > Signed-off-by: Vineet Gupta <vgu...@synopsys.com> > --- > arch/arc/kernel/time.c | 19 +++++++++++-------- > 1 file changed, 11 insertions(+), 8 deletions(-) > > diff --git a/arch/arc/kernel/time.c b/arch/arc/kernel/time.c > index f927b8dc6edd..1a117b999c0c 100644 > --- a/arch/arc/kernel/time.c > +++ b/arch/arc/kernel/time.c > @@ -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)));
I think original Daniel's comment was about constant value used here. Now with "_BITUL" it already looks much better but IMHO it would be even better if 31 gets converted here to something like: ------------------------>8-------------------- #define RTC_CTRL_A1_OFFSET 31 ------------------------>8-------------------- -Alexey _______________________________________________ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc
