From 0774c2b5c1e0025cb016393d8552171c0ec55c39 Mon Sep 17 00:00:00 2001
From: Ian Abbott <abbotti@mev.co.uk>
Date: Mon, 3 Dec 2012 18:15:40 +0000
Subject: [PATCH] staging: comedi: addi_apci_2032: interrupt safety change
Put the hardware into a safe state before enabling the interrupt. In
the interrupt routine, check the device has been fully configured by
checking `dev->attached`. In particular, `dev->read_subdev` could be
NULL early on and although the hardware's status register should
indicate no interrupt has occurred (since it's been put into a safe
state), it's better not to rely on it.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/staging/comedi/drivers/addi_apci_2032.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/staging/comedi/drivers/addi_apci_2032.c b/drivers/staging/comedi/drivers/addi_apci_2032.c
index 8f8d3e95fc78..3b5e1d74d129 100644
--- a/drivers/staging/comedi/drivers/addi_apci_2032.c
+++ b/drivers/staging/comedi/drivers/addi_apci_2032.c
@@ -237,6 +237,9 @@ static irqreturn_t apci2032_interrupt(int irq, void *d)
struct comedi_subdevice *s = dev->read_subdev;
unsigned int val;
+ if (!dev->attached)
+ return IRQ_NONE;
+
/* Check if VCC OR CC interrupt has occurred */
val = inl(dev->iobase + APCI2032_STATUS_REG) & APCI2032_STATUS_IRQ;
if (!val)
@@ -281,6 +284,7 @@ static int apci2032_auto_attach(struct comedi_device *dev,
if (ret)
return ret;
dev->iobase = pci_resource_start(pcidev, 1);
+ apci2032_reset(dev);
if (pcidev->irq > 0) {
ret = request_irq(pcidev->irq, apci2032_interrupt,
@@ -329,7 +333,6 @@ static int apci2032_auto_attach(struct comedi_device *dev,
s->type = COMEDI_SUBD_UNUSED;
}
- apci2032_reset(dev);
return 0;
}
--
2.34.1