Re: [PATCH 2/3] ARM: at91/tc/clocksource: improve driver robustness

From: Nicolas Ferre
Date: Wed Oct 02 2013 - 08:47:41 EST


On 02/10/2013 14:35, Boris BREZILLON :
Check function return values to avoid false positive driver init.

Signed-off-by: Boris BREZILLON <b.brezillon@xxxxxxxxxxx>

Acked-by: Nicolas Ferre <nicolas.ferre@xxxxxxxxx>

---
drivers/clocksource/tcb_clksrc.c | 33 ++++++++++++++++++++++++++++-----
1 file changed, 28 insertions(+), 5 deletions(-)

diff --git a/drivers/clocksource/tcb_clksrc.c b/drivers/clocksource/tcb_clksrc.c
index 0481562..10a5d9e 100644
--- a/drivers/clocksource/tcb_clksrc.c
+++ b/drivers/clocksource/tcb_clksrc.c
@@ -184,11 +184,18 @@ static struct irqaction tc_irqaction = {
.handler = ch2_irq,
};

-static void __init setup_clkevents(struct atmel_tc *tc, int clk32k_divisor_idx)
+static int __init setup_clkevents(struct atmel_tc *tc, int clk32k_divisor_idx)
{
+ int ret;
struct clk *t2_clk = tc->clk[2];
int irq = tc->irq[2];

+ /* try to enable t2 clk to avoid future errors in mode change */
+ ret = clk_prepare_enable(t2_clk);
+ if (ret)
+ return ret;
+ clk_disable_unprepare(t2_clk);
+
clkevt.regs = tc->regs;
clkevt.clk = t2_clk;
tc_irqaction.dev_id = &clkevt;
@@ -197,16 +204,21 @@ static void __init setup_clkevents(struct atmel_tc *tc, int clk32k_divisor_idx)

clkevt.clkevt.cpumask = cpumask_of(0);

+ ret = setup_irq(irq, &tc_irqaction);
+ if (ret)
+ return ret;
+
clockevents_config_and_register(&clkevt.clkevt, 32768, 1, 0xffff);

- setup_irq(irq, &tc_irqaction);
+ return ret;
}

#else /* !CONFIG_GENERIC_CLOCKEVENTS */

-static void __init setup_clkevents(struct atmel_tc *tc, int clk32k_divisor_idx)
+static int __init setup_clkevents(struct atmel_tc *tc, int clk32k_divisor_idx)
{
/* NOTHING */
+ return 0;
}

#endif
@@ -328,13 +340,24 @@ static int __init tcb_clksrc_init(void)
}

/* and away we go! */
- clocksource_register_hz(&clksrc, divided_rate);
+ ret = clocksource_register_hz(&clksrc, divided_rate);
+ if (ret)
+ goto err_disable_t1;

/* channel 2: periodic and oneshot timer support */
- setup_clkevents(tc, clk32k_divisor_idx);
+ ret = setup_clkevents(tc, clk32k_divisor_idx);
+ if (ret)
+ goto err_unregister_clksrc;

return 0;

+err_unregister_clksrc:
+ clocksource_unregister(&clksrc);
+
+err_disable_t1:
+ if (!tc->tcb_config || tc->tcb_config->counter_width != 32)
+ clk_disable_unprepare(tc->clk[1]);
+
err_disable_t0:
clk_disable_unprepare(t0_clk);




--
Nicolas Ferre
--
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