posix clocks: correct error value in posix_clock_poll()

PATCH In review Nicolas Kaiser 2 participants 3 messages May 24, 2011 Posix clocks and timers

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Nicolas Kaiser

author

2011-05-24 10:55 UTC #0 lore raw

PATCH 1/1 posix clocks: correct error value in posix_clock_poll()

Signed-off-by Nicolas Kaiser <[email protected]>

---
It looks to me like -ENODEV might not be a good return value in poll(). Would POLLERR be the correct one in this case?

 kernel/time/posix-clock.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

kernel/time/posix-clock.c +1 -1

index c340ca6..2424d3f 100644
@@ -71,7 +71,7 @@ static unsigned int posix_clock_poll(struct file *fp, poll_table *wait)
 	int result = 0;
 
 	if (!clk)
-		return -ENODEV;
+		return POLLERR;
 
 	if (clk->ops.poll)
 		result = clk->ops.poll(clk, fp, wait);

Signature · 1 line

1.7.5.rc3

Richard Cochran

2011-05-24 12:34 UTC #1 lore raw

Quoted 13 lines · Nicolas Kaiser

Signed-off-by Nicolas Kaiser <[email protected]>
---
It looks to me like -ENODEV might not be a good return value in poll(). Would POLLERR be the correct one in this case?
 kernel/time/posix-clock.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
kernel/time/posix-clock.c +0 -0
index c340ca6..2424d3f 100644

kernel/time/posix-clock.c static unsigned int posix_clock_poll(struct file *fp, poll_table *wait) · line 74

Quoted 5 lines

kernel/time/posix-clock.c +1 -1

@@ -71,7 +71,7 @@ static unsigned int posix_clock_poll(struct file *fp, poll_table *wait)
 	int result = 0;
 
 	if (!clk)
-		return -ENODEV;
+		return POLLERR;

The condition (!clk) is only satisfied when 'zombie' is set, indicating that the dynamic clock has disappeared. That is why the file operations uniformly return ENODEV. So, I think it makes sense the way that it is.

In addition, man 2 poll says,

POLLERR
Error condition (output only).

so using that error code would be misleading, IMHO.

Thanks,
Richard

Nicolas Kaiser

author

2011-05-24 14:09 UTC #2 lore raw

* Richard Cochran <[email protected]>:

Quoted 9 lines · Nicolas Kaiser

Quoted 2 lines
It looks to me like -ENODEV might not be a good return value in poll(). Would POLLERR be the correct one in this case?
The condition (!clk) is only satisfied when 'zombie' is set, indicating that the dynamic clock has disappeared. That is why the file operations uniformly return ENODEV. So, I think it makes sense the way that it is.

Quoted 6 lines

In addition, man 2 poll says,
POLLERR
Error condition (output only).
so using that error code would be misleading, IMHO.

I see. Sorry for the noise.

Best regards,
Nicolas Kaiser