Thread (16 messages) 16 messages, 3 authors, 2012-02-10
STALE5227d

[PATCH 2/6] mfd: mc13xxx-core: ADC conv: wait_for_completion returns a long

From: Uwe Kleine-König <hidden>
Date: 2012-01-30 07:24:53

On Mon, Jan 30, 2012 at 09:33:24AM +1100, Marc Reilly wrote:
Use the correct return type for wait_for_completion, as long may be
larger than int.
That's a theoretical problem only because the return value should be in
the range -ESOMETHING ... HZ which fits into an int.
quoted hunk ↗ jump to hunk
Signed-off-by: Marc Reilly <redacted>
---
 drivers/mfd/mc13xxx-core.c |   14 +++++++++-----
 1 files changed, 9 insertions(+), 5 deletions(-)
diff --git a/drivers/mfd/mc13xxx-core.c b/drivers/mfd/mc13xxx-core.c
index 8cb83ef..afff892 100644
--- a/drivers/mfd/mc13xxx-core.c
+++ b/drivers/mfd/mc13xxx-core.c
@@ -513,6 +513,7 @@ int mc13xxx_adc_do_conversion(struct mc13xxx *mc13xxx, unsigned int mode,
 {
 	u32 adc0, adc1, old_adc0;
 	int i, ret;
+	long timeout;
 	struct mc13xxx_adcdone_data adcdone_data = {
 		.mc13xxx = mc13xxx,
 	};
@@ -566,20 +567,23 @@ int mc13xxx_adc_do_conversion(struct mc13xxx *mc13xxx, unsigned int mode,
 			mc13xxx_handler_adcdone, __func__, &adcdone_data);
 
 	mc13xxx_reg_write(mc13xxx, MC13XXX_ADC0, adc0);
-	mc13xxx_reg_write(mc13xxx, MC13XXX_ADC1, adc1);
+	ret = mc13xxx_reg_write(mc13xxx, MC13XXX_ADC1, adc1);
Is this change intended? I guess without it you get a warning that ret
is used uninitialized, but if mc13xxx_reg_write fails you should IMHO
return at once.
 
 	mc13xxx_unlock(mc13xxx);
 
-	ret = wait_for_completion_interruptible_timeout(&adcdone_data.done, HZ);
+	timeout = wait_for_completion_interruptible_timeout(&adcdone_data.done, HZ);
 
-	if (!ret)
+	if (timeout <= 0) {
+		dev_warn(mc13xxx->dev,
+				"timed out waiting for ADC completion\n");
 		ret = -ETIMEDOUT;
+	}
I think this is wrong. wait_for_completion_interruptible_timeout returns
-ERESTARTSYS if it was interrupted. That's not a timeout and
-ERESTARTSYS should be propagated then. !ret is the correct test for
timeout.
 
 	mc13xxx_lock(mc13xxx);
 
 	mc13xxx_irq_free(mc13xxx, MC13XXX_IRQ_ADCDONE, &adcdone_data);
 
-	if (ret > 0)
+	if (!ret)
This is wrong, too, isn't it?
 		for (i = 0; i < 4; ++i) {
 			ret = mc13xxx_reg_read(mc13xxx,
 					MC13XXX_ADC2, &sample[i]);
Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-K?nig            |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
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