Attachment 195014 Details for Bug 229644 – possible workaround for allwinner timer glitches

[patch] possible workaround for allwinner timer glitches

a64unstable_generic_timer.diff (text/plain), 2.19 KB, created by Ian Lepore on 2018-07-09 22:47:32 UTC

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Creator: Ian Lepore

Created: 2018-07-09 22:47:32 UTC

Size: 2.19 KB

patch

obsolete

>Index: sys/arm/arm/generic_timer.c
>===================================================================
>--- sys/arm/arm/generic_timer.c	(revision 336112)
>+++ sys/arm/arm/generic_timer.c	(working copy)
>@@ -178,6 +178,19 @@ get_cntxct(bool physical)
> 	return (val);
> }
> 
>+static uint64_t
>+get_cntxcval(bool physical)
>+{
>+	uint64_t val;
>+
>+	if (physical)
>+		val = get_el0(cntp_cval);
>+	else
>+		val = get_el0(cntv_cval);
>+
>+	return (val);
>+}
>+
> static int
> set_ctrl(uint32_t val, bool physical)
> {
>@@ -275,6 +288,38 @@ arm_tmr_start(struct eventtimer *et, sbintime_t fi
> 
> }
> 
>+static int
>+arm_tmr_start_a64_unstable(struct eventtimer *et, sbintime_t first,
>+    sbintime_t period __unused)
>+{
>+	struct arm_tmr_softc *sc;
>+	int counts, ctrl, retries;
>+	const int max_tries = 10;
>+	uint64_t cntreg, cval, tval;
>+
>+	sc = (struct arm_tmr_softc *)et->et_priv;
>+
>+	if (first == 0)
>+		return (EINVAL);
>+
>+	ctrl = get_ctrl(sc->physical);
>+	ctrl &= ~GT_CTRL_INT_MASK;
>+	ctrl |= GT_CTRL_ENABLE;
>+	counts = ((uint32_t)et->et_frequency * first) >> 32;
>+	for (retries = 0; retries < max_tries; ++retries) {
>+		cntreg = get_cntxct(sc->physical);
>+		set_tval(counts, sc->physical);
>+		cval = get_cntxcval(sc->physical);
>+		tval = cval - cntreg;
>+		if (tval - counts < 40)
>+			break;
>+	}
>+
>+	set_ctrl(ctrl, sc->physical);
>+	return (0);
>+
>+}
>+
> static void
> arm_tmr_disable(bool physical)
> {
>@@ -397,7 +442,9 @@ arm_tmr_attach(device_t dev)
> #endif
> 	int error;
> 	int i;
>+	bool a64_unstable;
> 
>+	a64_unstable = false;
> 	sc = device_get_softc(dev);
> 	if (arm_tmr_sc)
> 		return (ENXIO);
>@@ -413,6 +460,7 @@ arm_tmr_attach(device_t dev)
> 			sc->clkfreq = clock;
> 
> 		if (OF_hasprop(node, "allwinner,sun50i-a64-unstable-timer")) {
>+			a64_unstable = true;
> 			sc->get_cntxct = &get_cntxct_a64_unstable;
> 			if (bootverbose)
> 				device_printf(dev,
>@@ -475,7 +523,7 @@ arm_tmr_attach(device_t dev)
> 	sc->et.et_frequency = sc->clkfreq;
> 	sc->et.et_min_period = (0x00000010LLU << 32) / sc->et.et_frequency;
> 	sc->et.et_max_period = (0xfffffffeLLU << 32) / sc->et.et_frequency;
>-	sc->et.et_start = arm_tmr_start;
>+	sc->et.et_start = (a64_unstable) ? arm_tmr_start_a64_unstable : arm_tmr_start;
> 	sc->et.et_stop = arm_tmr_stop;
> 	sc->et.et_priv = sc;
> 	et_register(&sc->et);

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Attachments on bug 229644: 195014 | 195033 | 195062 | 196420