---

yaml
---
r: 339920
b: refs/heads/master
c: bfd6d02
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 971d0254480572bc6dc5574c28ef8fe014660a31
+refs/heads/master: bfd6d021120d5994c4cc94d87ec03642be1540e7

trunk/arch/arm/mach-omap2/timer.c

@@ -222,10 +222,24 @@ void __init omap_dmtimer_init(void)
 	}
 }
 
+/**
+ * omap_dm_timer_get_errata - get errata flags for a timer
+ *
+ * Get the timer errata flags that are specific to the OMAP device being used.
+ */
+u32 __init omap_dm_timer_get_errata(void)
+{
+	if (cpu_is_omap24xx())
+		return 0;
+
+	return OMAP_TIMER_ERRATA_I103_I767;
+}
+
 static int __init omap_dm_timer_init_one(struct omap_dm_timer *timer,
 						int gptimer_id,
 						const char *fck_source,
-						const char *property)
+						const char *property,
+						int posted)
 {
 	char name[10]; /* 10 = sizeof("gptXX_Xck0") */
 	const char *oh_name;
@@ -311,10 +325,15 @@ static int __init omap_dm_timer_init_one(struct omap_dm_timer *timer,
 	}
 	__omap_dm_timer_init_regs(timer);
 	__omap_dm_timer_reset(timer, 1, 1);
-	timer->posted = 1;
 
-	timer->rate = clk_get_rate(timer->fclk);
+	if (posted)
+		__omap_dm_timer_enable_posted(timer);
+
+	/* Check that the intended posted configuration matches the actual */
+	if (posted != timer->posted)
+		return -EINVAL;
 
+	timer->rate = clk_get_rate(timer->fclk);
 	timer->reserved = 1;
 
 	return res;
@@ -326,7 +345,17 @@ static void __init omap2_gp_clockevent_init(int gptimer_id,
 {
 	int res;
 
-	res = omap_dm_timer_init_one(&clkev, gptimer_id, fck_source, property);
+	clkev.errata = omap_dm_timer_get_errata();
+
+	/*
+	 * For clock-event timers we never read the timer counter and
+	 * so we are not impacted by errata i103 and i767. Therefore,
+	 * we can safely ignore this errata for clock-event timers.
+	 */
+	__omap_dm_timer_override_errata(&clkev, OMAP_TIMER_ERRATA_I103_I767);
+
+	res = omap_dm_timer_init_one(&clkev, gptimer_id, fck_source, property,
+				     OMAP_TIMER_POSTED);
 	BUG_ON(res);
 
 	omap2_gp_timer_irq.dev_id = &clkev;
@@ -360,7 +389,7 @@ static bool use_gptimer_clksrc;
 static cycle_t clocksource_read_cycles(struct clocksource *cs)
 {
 	return (cycle_t)__omap_dm_timer_read_counter(&clksrc,
-						     OMAP_TIMER_POSTED);
+						     OMAP_TIMER_NONPOSTED);
 }
 
 static struct clocksource clocksource_gpt = {
@@ -375,7 +404,7 @@ static u32 notrace dmtimer_read_sched_clock(void)
 {
 	if (clksrc.reserved)
 		return __omap_dm_timer_read_counter(&clksrc,
-						    OMAP_TIMER_POSTED);
+						    OMAP_TIMER_NONPOSTED);
 
 	return 0;
 }
@@ -453,12 +482,15 @@ static void __init omap2_gptimer_clocksource_init(int gptimer_id,
 {
 	int res;
 
-	res = omap_dm_timer_init_one(&clksrc, gptimer_id, fck_source, NULL);
+	clksrc.errata = omap_dm_timer_get_errata();
+
+	res = omap_dm_timer_init_one(&clksrc, gptimer_id, fck_source, NULL,
+				     OMAP_TIMER_NONPOSTED);
 	BUG_ON(res);
 
 	__omap_dm_timer_load_start(&clksrc,
 				   OMAP_TIMER_CTRL_ST | OMAP_TIMER_CTRL_AR, 0,
-				   OMAP_TIMER_POSTED);
+				   OMAP_TIMER_NONPOSTED);
 	setup_sched_clock(dmtimer_read_sched_clock, 32, clksrc.rate);
 
 	if (clocksource_register_hz(&clocksource_gpt, clksrc.rate))
@@ -696,6 +728,7 @@ static int __init omap_timer_init(struct omap_hwmod *oh, void *unused)
 	if (timer_dev_attr)
 		pdata->timer_capability = timer_dev_attr->timer_capability;
 
+	pdata->timer_errata = omap_dm_timer_get_errata();
 	pdata->get_context_loss_count = omap_pm_get_dev_context_loss_count;
 
 	pdev = omap_device_build(name, id, oh, pdata, sizeof(*pdata),

trunk/arch/arm/plat-omap/dmtimer.c

@@ -128,8 +128,8 @@ static void omap_dm_timer_reset(struct omap_dm_timer *timer)
 	}
 
 	__omap_dm_timer_reset(timer, 0, 0);
+	__omap_dm_timer_enable_posted(timer);
 	omap_dm_timer_disable(timer);
-	timer->posted = 1;
 }
 
 int omap_dm_timer_prepare(struct omap_dm_timer *timer)
@@ -797,6 +797,7 @@ static int __devinit omap_dm_timer_probe(struct platform_device *pdev)
 			timer->capability |= OMAP_TIMER_SECURE;
 	} else {
 		timer->id = pdev->id;
+		timer->errata = pdata->timer_errata;
 		timer->capability = pdata->timer_capability;
 		timer->reserved = omap_dm_timer_reserved_systimer(timer->id);
 		timer->get_context_loss_count = pdata->get_context_loss_count;

trunk/arch/arm/plat-omap/include/plat/dmtimer.h

@@ -66,6 +66,16 @@
 #define OMAP_TIMER_NEEDS_RESET				0x10000000
 #define OMAP_TIMER_HAS_DSP_IRQ				0x08000000
 
+/*
+ * timer errata flags
+ *
+ * Errata i103/i767 impacts all OMAP3/4/5 devices including AM33xx. This
+ * errata prevents us from using posted mode on these devices, unless the
+ * timer counter register is never read. For more details please refer to
+ * the OMAP3/4/5 errata documents.
+ */
+#define OMAP_TIMER_ERRATA_I103_I767			0x80000000
+
 struct omap_timer_capability_dev_attr {
 	u32 timer_capability;
 };
@@ -97,6 +107,7 @@ struct timer_regs {
 struct dmtimer_platform_data {
 	/* set_timer_src - Only used for OMAP1 devices */
 	int (*set_timer_src)(struct platform_device *pdev, int source);
+	u32 timer_errata;
 	u32 timer_capability;
 	int (*get_context_loss_count)(struct device *);
 };
@@ -273,6 +284,7 @@ struct omap_dm_timer {
 	int ctx_loss_count;
 	int revision;
 	u32 capability;
+	u32 errata;
 	struct platform_device *pdev;
 	struct list_head node;
 };
@@ -344,10 +356,46 @@ static inline void __omap_dm_timer_reset(struct omap_dm_timer *timer,
 		l |= 1 << 2;
 
 	__raw_writel(l, timer->io_base + OMAP_TIMER_OCP_CFG_OFFSET);
+}
+
+/*
+ * __omap_dm_timer_enable_posted - enables write posted mode
+ * @timer:      pointer to timer instance handle
+ *
+ * Enables the write posted mode for the timer. When posted mode is enabled
+ * writes to certain timer registers are immediately acknowledged by the
+ * internal bus and hence prevents stalling the CPU waiting for the write to
+ * complete. Enabling this feature can improve performance for writing to the
+ * timer registers.
+ */
+static inline void __omap_dm_timer_enable_posted(struct omap_dm_timer *timer)
+{
+	if (timer->posted)
+		return;
+
+	if (timer->errata & OMAP_TIMER_ERRATA_I103_I767)
+		return;
 
-	/* Match hardware reset default of posted mode */
 	__omap_dm_timer_write(timer, OMAP_TIMER_IF_CTRL_REG,
-					OMAP_TIMER_CTRL_POSTED, 0);
+			      OMAP_TIMER_CTRL_POSTED, 0);
+	timer->context.tsicr = OMAP_TIMER_CTRL_POSTED;
+	timer->posted = OMAP_TIMER_POSTED;
+}
+
+/**
+ * __omap_dm_timer_override_errata - override errata flags for a timer
+ * @timer:      pointer to timer handle
+ * @errata:	errata flags to be ignored
+ *
+ * For a given timer, override a timer errata by clearing the flags
+ * specified by the errata argument. A specific erratum should only be
+ * overridden for a timer if the timer is used in such a way the erratum
+ * has no impact.
+ */
+static inline void __omap_dm_timer_override_errata(struct omap_dm_timer *timer,
+						   u32 errata)
+{
+	timer->errata &= ~errata;
 }
 
 static inline int __omap_dm_timer_set_source(struct clk *timer_fck,