3.6.11.2 stable review patch. If anyone has any objections, please let me know. ------------------ From: Ian Abbott [ Upstream commit e4317ce877a31dbb9d96375391c1c4ad2210d637 ] For the s626 driver, there is a bug in the handling of asynchronous commands on the AI subdevice when the stop source is `TRIG_NONE`. The command should run continuously until cancelled, but the interrupt handler stops the command running after the first scan. The command set-up function `s626_ai_cmd()` contains this code: switch (cmd->stop_src) { case TRIG_COUNT: /* data arrives as one packet */ devpriv->ai_sample_count = cmd->stop_arg; devpriv->ai_continous = 0; break; case TRIG_NONE: /* continous acquisition */ devpriv->ai_continous = 1; devpriv->ai_sample_count = 0; break; } The interrupt handler `s626_irq_handler()` contains this code: if (!(devpriv->ai_continous)) devpriv->ai_sample_count--; if (devpriv->ai_sample_count <= 0) { devpriv->ai_cmd_running = 0; /* ... */ } So `devpriv->ai_sample_count` is only decremented for the `TRIG_COUNT` case, but `devpriv->ai_cmd_running` is set to 0 (and the command stopped) regardless. Fix this in `s626_ai_cmd()` by setting `devpriv->ai_sample_count = 1` for the `TRIG_NONE` case. The interrupt handler will not decrement it so it will remain greater than 0 and the check for stopping the acquisition will fail. Cc: stable Signed-off-by: Ian Abbott Signed-off-by: Greg Kroah-Hartman Signed-off-by: Steven Rostedt --- drivers/staging/comedi/drivers/s626.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/staging/comedi/drivers/s626.c b/drivers/staging/comedi/drivers/s626.c index 2b03b68..f809ef3 100644 --- a/drivers/staging/comedi/drivers/s626.c +++ b/drivers/staging/comedi/drivers/s626.c @@ -1509,7 +1509,7 @@ static int s626_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s) case TRIG_NONE: /* continous acquisition */ devpriv->ai_continous = 1; - devpriv->ai_sample_count = 0; + devpriv->ai_sample_count = 1; break; } -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/