On Thu, 14 Jun 2018 12:26:38 -0500 Kyle Evans <[email protected]> wrote:
> On Thu, Jun 14, 2018 at 12:18 PM, Emmanuel Vadot <[email protected]> wrote: > > Author: manu > > Date: Thu Jun 14 17:18:15 2018 > > New Revision: 335156 > > URL: https://svnweb.freebsd.org/changeset/base/335156 > > > > Log: > > arm timer: Add workaround for Allwinner A64 timer > > > > The timer present in allwinner A64 SoC is unstable, value can jump > > backward > > or forward. > > It was found that when bit 11 and upper roll over the low bits can > > sometimes > > being read as all as 1 or all as 0. > > Simply ignore the values for those cases. > > > > Modified: > > head/sys/arm/arm/generic_timer.c > > > > Modified: head/sys/arm/arm/generic_timer.c > > ============================================================================== > > --- head/sys/arm/arm/generic_timer.c Thu Jun 14 17:09:33 2018 > > (r335155) > > +++ head/sys/arm/arm/generic_timer.c Thu Jun 14 17:18:15 2018 > > (r335156) > > @@ -92,6 +92,7 @@ __FBSDID("$FreeBSD$"); > > struct arm_tmr_softc { > > struct resource *res[4]; > > void *ihl[4]; > > + uint64_t (*get_cntxct)(bool); > > uint32_t clkfreq; > > struct eventtimer et; > > bool physical; > > @@ -142,6 +143,28 @@ get_freq(void) > > } > > > > static uint64_t > > +get_cntxct_a64_unstable(bool physical) > > +{ > > + uint64_t val > > +; > > + isb(); > > + if (physical) { > > + do { > > + val = get_el0(cntpct); > > + } > > + while (((val + 1) & 0x7FF) <= 1); > > + } > > + else { > > + do { > > + val = get_el0(cntvct); > > + } > > + while (((val + 1) & 0x7FF) <= 1); > > + } > > + > > + return (val); > > +} > > + > > +static uint64_t > > get_cntxct(bool physical) > > { > > uint64_t val; > > @@ -226,7 +249,7 @@ static unsigned > > arm_tmr_get_timecount(struct timecounter *tc) > > { > > > > - return (get_cntxct(arm_tmr_sc->physical)); > > + return (arm_tmr_sc->get_cntxct(arm_tmr_sc->physical)); > > } > > > > static int > > @@ -379,6 +402,7 @@ arm_tmr_attach(device_t dev) > > if (arm_tmr_sc) > > return (ENXIO); > > > > + sc->get_cntxct = &get_cntxct_a64_unstable; > > #ifdef FDT > > /* Get the base clock frequency */ > > node = ofw_bus_get_node(dev); > > Was it intentional to set sc->get_cntxct to get_cntxct_a64_unstable in > the general case? Seems like this should've been get_cntxct. Fixed in 335161. Thanks, > > @@ -387,6 +411,13 @@ arm_tmr_attach(device_t dev) > > sizeof(clock)); > > if (error > 0) > > sc->clkfreq = clock; > > + > > + if (OF_hasprop(node, > > "allwinner,sun50i-a64-unstable-timer")) { > > + sc->get_cntxct = &get_cntxct_a64_unstable; > > + if (bootverbose) > > + device_printf(dev, > > + "Enabling allwinner unstable timer > > workaround\n"); > > + } > > } > > #endif > > > > Since the a64-specific get_cntxct is set here. > > > @@ -518,10 +549,10 @@ arm_tmr_do_delay(int usec, void *arg) > > else > > counts = usec * counts_per_usec; > > > > - first = get_cntxct(sc->physical); > > + first = sc->get_cntxct(sc->physical); > > > > while (counts > 0) { > > - last = get_cntxct(sc->physical); > > + last = sc->get_cntxct(sc->physical); > > counts -= (int32_t)(last - first); > > first = last; > > } > > _______________________________________________ > > [email protected] mailing list > > https://lists.freebsd.org/mailman/listinfo/svn-src-head > > To unsubscribe, send any mail to "[email protected]" -- Emmanuel Vadot <[email protected]> <[email protected]> _______________________________________________ [email protected] mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "[email protected]"
