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From: Nicholas Mc Guire <>
To: Jonathan Cameron <>
Cc: Hartmut Knaack <>,
	Lars-Peter Clausen <>,
	Peter Meerwald <>,
	"Ivan T. Ivanov" <>,,,
	Nicholas Mc Guire <>
Subject: [PATCH 2/3] iio: qcom-spmi-iadc: cleanup wait_for_completion return handling
Date: Mon,  2 Feb 2015 03:37:07 -0500	[thread overview]
Message-ID: <> (raw)

This patch fixes two issues:
* return type of wait_for_completion_timeout is unsigned long not int, 
  rather than adding a dedicated variable the wait_for_completion_timeout
  is moved into the condition directly
* the timeout of wait_for_completion_timeout is in jiffies but the value
  being passed was a unsigned long not converted to jiffies and thus was
  dependent on the HZ settings which is probably not what you want.

Signed-off-by: Nicholas Mc Guire <>

Note that the timeout value changed very significantly as wait was 
initially in the range of 2 milliseconds, so this converts to 1 jiffies
for HZ < 1000 and 2 jiffies for HZ=1000 - thus the timeout value changed
by 3 orders of magnitude. This needs a review by someone that knows the
details of the hardware to judge if this change is ok - in any case the
timeout passed should go through usecs_to_jiffies or msecs_to_jiffis and
to ensure it is no longer HZ dependent.

Patch was compile tested only for imx_v6_v7_defconfig + CONFIG_IIO=m

Patch is against 3.19.0-rc6 -next-20150130

 drivers/iio/adc/qcom-spmi-iadc.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/adc/qcom-spmi-iadc.c b/drivers/iio/adc/qcom-spmi-iadc.c
index b9666f2..61fb88d 100644
--- a/drivers/iio/adc/qcom-spmi-iadc.c
+++ b/drivers/iio/adc/qcom-spmi-iadc.c
@@ -296,8 +296,8 @@ static int iadc_do_conversion(struct iadc_chip *iadc, int chan, u16 *data)
 	if (iadc->poll_eoc) {
 		ret = iadc_poll_wait_eoc(iadc, wait);
 	} else {
-		ret = wait_for_completion_timeout(&iadc->complete, wait);
-		if (!ret)
+		if (!wait_for_completion_timeout(&iadc->complete, 
+				usecs_to_jiffies(wait)))
 			ret = -ETIMEDOUT;
 			/* double check conversion status */

             reply	other threads:[~2015-02-02  8:41 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-02-02  8:37 Nicholas Mc Guire [this message]
2015-02-04 16:59 ` Jonathan Cameron
2015-02-05 12:23   ` Ivan T. Ivanov

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