From 9c922a9076afd9e483bc17d768ed813d2f76f7cb Mon Sep 17 00:00:00 2001 From: H Hartley Sweeten Date: Thu, 25 Jul 2013 16:21:13 -0700 Subject: [PATCH] staging: comedi: usbduxsigma: set *_cmd_running flags before submitting urbs As pointed out by Ian Abbott, the *_cmd_running flags should be set before submitting the urbs. There is a possible race condition where an urb could complete and the flag is checked in the completion routine before it's set. Reported-by: Ian Abbott Acked-by: Ian Abbott Reviewed-by: Ian Abbott Signed-off-by: H Hartley Sweeten Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/drivers/usbduxsigma.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) diff --git a/drivers/staging/comedi/drivers/usbduxsigma.c b/drivers/staging/comedi/drivers/usbduxsigma.c index 40eeb8c68306..1af235407eb4 100644 --- a/drivers/staging/comedi/drivers/usbduxsigma.c +++ b/drivers/staging/comedi/drivers/usbduxsigma.c @@ -686,13 +686,14 @@ static int usbduxsigma_ai_inttrig(struct comedi_device *dev, down(&devpriv->sem); if (!devpriv->ai_cmd_running) { + devpriv->ai_cmd_running = 1; ret = usbduxsigma_submit_urbs(dev, devpriv->ai_urbs, devpriv->n_ai_urbs, 1); if (ret < 0) { + devpriv->ai_cmd_running = 0; up(&devpriv->sem); return ret; } - devpriv->ai_cmd_running = 1; s->async->inttrig = NULL; } up(&devpriv->sem); @@ -740,14 +741,15 @@ static int usbduxsigma_ai_cmd(struct comedi_device *dev, if (cmd->start_src == TRIG_NOW) { /* enable this acquisition operation */ + devpriv->ai_cmd_running = 1; ret = usbduxsigma_submit_urbs(dev, devpriv->ai_urbs, devpriv->n_ai_urbs, 1); if (ret < 0) { + devpriv->ai_cmd_running = 0; up(&devpriv->sem); return ret; } s->async->inttrig = NULL; - devpriv->ai_cmd_running = 1; } else { /* TRIG_INT */ /* wait for an internal signal and submit the urbs later */ s->async->inttrig = usbduxsigma_ai_inttrig; @@ -876,13 +878,14 @@ static int usbduxsigma_ao_inttrig(struct comedi_device *dev, down(&devpriv->sem); if (!devpriv->ao_cmd_running) { + devpriv->ao_cmd_running = 1; ret = usbduxsigma_submit_urbs(dev, devpriv->ao_urbs, devpriv->n_ao_urbs, 0); if (ret < 0) { + devpriv->ao_cmd_running = 0; up(&devpriv->sem); return ret; } - devpriv->ao_cmd_running = 1; s->async->inttrig = NULL; } up(&devpriv->sem); @@ -1026,14 +1029,15 @@ static int usbduxsigma_ao_cmd(struct comedi_device *dev, if (cmd->start_src == TRIG_NOW) { /* enable this acquisition operation */ + devpriv->ao_cmd_running = 1; ret = usbduxsigma_submit_urbs(dev, devpriv->ao_urbs, devpriv->n_ao_urbs, 0); if (ret < 0) { + devpriv->ao_cmd_running = 0; up(&devpriv->sem); return ret; } s->async->inttrig = NULL; - devpriv->ao_cmd_running = 1; } else { /* TRIG_INT */ /* wait for an internal signal and submit the urbs later */ s->async->inttrig = usbduxsigma_ao_inttrig; @@ -1237,10 +1241,12 @@ static int usbduxsigma_pwm_start(struct comedi_device *dev, memset(devpriv->pwm_urb->transfer_buffer, 0, devpriv->pwm_buf_sz); + devpriv->pwm_cmd_running = 1; ret = usbduxsigma_submit_pwm_urb(dev); - if (ret < 0) + if (ret < 0) { + devpriv->pwm_cmd_running = 0; return ret; - devpriv->pwm_cmd_running = 1; + } return 0; } -- 2.11.0