Re: Notification when a new device is added or removed

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

On Sat, Feb 28, 2009 at 06:58:05PM -0800, Alessio Sangalli wrote:
> Dmitry Torokhov wrote:
> 
> > You should be able to poll (select) /proc/bus/input/devices.
> 
> Yeah that would be great; anyway, I tried and... well nothing happens. I
> am obviously missing something here:
> 

Hmm, it turns out poll is completely busted. The patch below should
help.

-- 
Dmitry

Input: fix polling of /proc/bus/input/devices

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
---

 drivers/input/input.c |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)


diff --git a/drivers/input/input.c b/drivers/input/input.c
index 46e9ce1..913392f 100644
--- a/drivers/input/input.c
+++ b/drivers/input/input.c
@@ -744,11 +744,11 @@ static inline void input_wakeup_procfs_readers(void)
 
 static unsigned int input_proc_devices_poll(struct file *file, poll_table *wait)
 {
-	int state = input_devices_state;
-
 	poll_wait(file, &input_devices_poll_wait, wait);
-	if (state != input_devices_state)
+	if (file->f_version != input_devices_state) {
+		file->f_version = input_devices_state;
 		return POLLIN | POLLRDNORM;
+	}
 
 	return 0;
 }