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authorBernd Porr <berndporr@f2s.com>2009-11-27 15:00:53 +0300
committerGreg Kroah-Hartman <gregkh@suse.de>2009-12-23 22:27:45 +0300
commitd4c3a56587af3edbe5f618b20e800e9f9fde13cb (patch)
treec5968064db803c106cc9486e00d795ac07c4ec9f /drivers/staging
parent29d249ed80c80b479df78e456e6809223c648505 (diff)
downloadlinux-d4c3a56587af3edbe5f618b20e800e9f9fde13cb.tar.xz
Staging: comedi: usbdux.c: fix locking up of the driver when the comedi ringbuffer runs empty
Jan-Matthias Braun spotted a bug which locks up the driver when the comedi ring buffer runs empty and provided a patch. The driver would still send the data to comedi but the reader won't wake up any more. What's required is setting the flag COMEDI_CB_BLOCK after new data has arrived which wakes up the reader and therefore the read() command. Signed-off-by: Bernd Porr <berndporr@f2s.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/staging')
-rw-r--r--drivers/staging/comedi/drivers/usbdux.c5
1 files changed, 4 insertions, 1 deletions
diff --git a/drivers/staging/comedi/drivers/usbdux.c b/drivers/staging/comedi/drivers/usbdux.c
index 06c020466298..9a1b559c4b0d 100644
--- a/drivers/staging/comedi/drivers/usbdux.c
+++ b/drivers/staging/comedi/drivers/usbdux.c
@@ -1,4 +1,4 @@
-#define DRIVER_VERSION "v2.3"
+#define DRIVER_VERSION "v2.4"
#define DRIVER_AUTHOR "Bernd Porr, BerndPorr@f2s.com"
#define DRIVER_DESC "Stirling/ITL USB-DUX -- Bernd.Porr@f2s.com"
/*
@@ -81,6 +81,8 @@ sampling rate. If you sample two channels you get 4kHz and so on.
* 2.1: changed PWM API
* 2.2: added firmware kernel request to fix an udev problem
* 2.3: corrected a bug in bulk timeouts which were far too short
+ * 2.4: fixed a bug which causes the driver to hang when it ran out of data.
+ * Thanks to Jan-Matthias Braun and Ian to spot the bug and fix it.
*
*/
@@ -532,6 +534,7 @@ static void usbduxsub_ai_IsocIrq(struct urb *urb)
}
}
/* tell comedi that data is there */
+ s->async->events |= COMEDI_CB_BLOCK | COMEDI_CB_EOS;
comedi_event(this_usbduxsub->comedidev, s);
}