Replace sprintf() with sysfs_emit() in sysfs attribute show functions.
sysfs_emit() is the preferred API for sysfs callbacks as it is aware
of the PAGE_SIZE buffer limit.

Also simplify the wavetype_available show functions by removing
the intermediate string variable and returning directly from each
branch.

Signed-off-by: Gabriel Rondon <grondon@gmail.com>
---
 drivers/staging/iio/frequency/ad9834.c | 20 ++++++--------------
 1 file changed, 6 insertions(+), 14 deletions(-)

diff --git a/drivers/staging/iio/frequency/ad9834.c b/drivers/staging/iio/frequency/ad9834.c
index d339d5e8e..bdb2580e2 100644
--- a/drivers/staging/iio/frequency/ad9834.c
+++ b/drivers/staging/iio/frequency/ad9834.c
@@ -281,16 +281,12 @@ ssize_t ad9834_show_out0_wavetype_available(struct device *dev,
 {
 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 	struct ad9834_state *st = iio_priv(indio_dev);
-	char *str;
 
 	if (st->devid == ID_AD9833 || st->devid == ID_AD9837)
-		str = "sine triangle square";
-	else if (st->control & AD9834_OPBITEN)
-		str = "sine";
-	else
-		str = "sine triangle";
-
-	return sprintf(buf, "%s\n", str);
+		return sysfs_emit(buf, "sine triangle square\n");
+	if (st->control & AD9834_OPBITEN)
+		return sysfs_emit(buf, "sine\n");
+	return sysfs_emit(buf, "sine triangle\n");
 }
 
 static IIO_DEVICE_ATTR(out_altvoltage0_out0_wavetype_available, 0444,
@@ -303,14 +299,10 @@ ssize_t ad9834_show_out1_wavetype_available(struct device *dev,
 {
 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 	struct ad9834_state *st = iio_priv(indio_dev);
-	char *str;
 
 	if (st->control & AD9834_MODE)
-		str = "";
-	else
-		str = "square";
-
-	return sprintf(buf, "%s\n", str);
+		return sysfs_emit(buf, "\n");
+	return sysfs_emit(buf, "square\n");
 }
 
 static IIO_DEVICE_ATTR(out_altvoltage0_out1_wavetype_available, 0444,
-- 
2.33.0

On Fri, 20 Mar 2026 22:24:24 +0000
Gabriel Rondon <grondon@gmail.com> wrote:

> Replace sprintf() with sysfs_emit() in sysfs attribute show functions.
> sysfs_emit() is the preferred API for sysfs callbacks as it is aware
> of the PAGE_SIZE buffer limit.
> 
> Also simplify the wavetype_available show functions by removing
> the intermediate string variable and returning directly from each
> branch.
> 
> Signed-off-by: Gabriel Rondon <grondon@gmail.com>
Similar to patch 2, I suspect this code will go through a lot of changes
if anyone does the work to move this driver out of staging.

So I'm applying this mostly to avoid anyone else sending patches
to do the same!

Applied.

Thanks,

Jonathan