[PATCH] stddev: make reads from /dev/null return 0 bytes

[PATCH] stddev: make reads from /dev/null return 0 bytes

[Ahmad Fatoum]

Currently, /dev/null discards all writes, but returns -ENOSYS on read.
Implement read to return 0 always, so it returns EOF immediately.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
---
 commands/stddev.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/commands/stddev.c b/commands/stddev.c
index e9b7dcc0d2f3..16cf4e30802d 100644
--- a/commands/stddev.c
+++ b/commands/stddev.c
@@ -64,8 +64,14 @@ static ssize_t null_write(struct cdev *cdev, const void *buf, size_t count, loff
 	return count;
 }
 
+static ssize_t null_read(struct cdev *cdev, void *buf, size_t count, loff_t offset, ulong flags)
+{
+	return 0;
+}
+
 static struct cdev_operations nullops = {
 	.write = null_write,
+	.read = null_read,
 };
 
 static int null_init(void)
-- 
2.39.5

Re: [PATCH] stddev: make reads from /dev/null return 0 bytes

[Sascha Hauer]

On Tue, 22 Apr 2025 09:54:44 +0200, Ahmad Fatoum wrote:
> Currently, /dev/null discards all writes, but returns -ENOSYS on read.
> Implement read to return 0 always, so it returns EOF immediately.
> 
> 

Applied, thanks!

[1/1] stddev: make reads from /dev/null return 0 bytes
      https://git.pengutronix.de/cgit/barebox/commit/?id=30f87370323a (link may not be stable)

Best regards,
-- 
Sascha Hauer <s.hauer@pengutronix.de>