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Commit ba5c0da8 authored by H Hartley Sweeten's avatar H Hartley Sweeten Committed by Greg Kroah-Hartman
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staging: comedi: ni_mio_common: fix interrupt handler for dev->read_subdev 



There may not be a dev->read_subdev, i.e. an analog input subdevice, that
supports async commands. If it doesn't exist the interrupt/dma will never
be enabled.  Fix ni_E_interrupt() so that the analog input subdevice is
only handled if it exists.

This also fixes minor NULL dereference issue in handle_a_interrupt().
If the dev->read_subdev is NULL the comedi_async pointer (s->async) will
not be allocated by the device postconfig so there is no way to get a
valid comedi_cmd (&s->async->cmd).

Signed-off-by: default avatarH Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: default avatarIan Abbott <abbotti@mev.co.uk>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 4b2d7389

drivers/staging/comedi/drivers/ni_mio_common.c

+9 −13
Original line number Diff line number Diff line
@@ -1288,19 +1288,13 @@ static void ack_a_interrupt(struct comedi_device *dev, unsigned short a_status) 
		ni_stc_writew(dev, ack, NISTC_INTA_ACK_REG);

}



static void handle_a_interrupt(struct comedi_device *dev, unsigned short status,

static void handle_a_interrupt(struct comedi_device *dev,

			       struct comedi_subdevice *s,

			       unsigned short status,

			       unsigned int ai_mite_status)

{

	struct comedi_subdevice *s = dev->read_subdev;

	struct comedi_cmd *cmd = &s->async->cmd;



	/*

	 * 67xx boards don't have ai subdevice, but their gpct0 might

	 * generate an a interrupt.

	 */

	if (s->type == COMEDI_SUBD_UNUSED)

		return;



#ifdef PCIDMA

	if (ai_mite_status & CHSR_LINKC)

		ni_sync_ai_dma(dev);
@@ -5148,6 +5142,7 @@ static int ni_gpct_cancel(struct comedi_device *dev, struct comedi_subdevice *s) 
static irqreturn_t ni_E_interrupt(int irq, void *d)

{

	struct comedi_device *dev = d;

	struct comedi_subdevice *s_ai = dev->read_subdev;

	struct comedi_subdevice *s_ao = dev->write_subdev;

	unsigned short a_status;

	unsigned short b_status;
@@ -5171,9 +5166,9 @@ static irqreturn_t ni_E_interrupt(int irq, void *d) 
		unsigned int m_status;



		spin_lock_irqsave(&devpriv->mite_channel_lock, flags_too);

		if (devpriv->ai_mite_chan)

		if (s_ai && devpriv->ai_mite_chan)

			ai_mite_status = mite_ack_linkc(devpriv->ai_mite_chan,

							dev->read_subdev);

							s_ai);



		if (s_ao && devpriv->ao_mite_chan) {

			m_status = mite_ack_linkc(devpriv->ao_mite_chan, s_ao);
@@ -5186,8 +5181,9 @@ static irqreturn_t ni_E_interrupt(int irq, void *d) 
#endif

	ack_a_interrupt(dev, a_status);

	ack_b_interrupt(dev, b_status);

	if ((a_status & NISTC_AI_STATUS1_INTA) || (ai_mite_status & CHSR_INT))

		handle_a_interrupt(dev, a_status, ai_mite_status);

	if (s_ai &&

	    ((a_status & NISTC_AI_STATUS1_INTA) || (ai_mite_status & CHSR_INT)))

		handle_a_interrupt(dev, s_ai, a_status, ai_mite_status);

	if (s_ao) {

		if (b_status & NISTC_AO_STATUS1_INTB)

			handle_b_interrupt(dev, s_ao, b_status);