Currently the dma buffers are freed during the detach of the driver using
the function s626_close_dma_b(). The buffers are also freed while the
interrupt handler is still attached. This could result in a race condition.
Refactor the code so that the buffers are freed after the interrupt handler
is released and the PCI device is disabled.
Signed-off-by: H Hartley Sweeten <hsweeten@xxxxxxxxxxxxxxxxxxx>
Cc: Ian Abbott <abbotti@xxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/staging/comedi/drivers/s626.c | 44 +++++++++++++++--------------------
1 file changed, 19 insertions(+), 25 deletions(-)
diff --git a/drivers/staging/comedi/drivers/s626.c b/drivers/staging/comedi/drivers/s626.c
index 080608a..304be83 100644
--- a/drivers/staging/comedi/drivers/s626.c
+++ b/drivers/staging/comedi/drivers/s626.c
@@ -2457,26 +2457,6 @@ static void s626_write_misc2(struct comedi_device *dev, uint16_t new_image)
s626_debi_write(dev, S626_LP_MISC1, S626_MISC1_WDISABLE);
}
-static void s626_close_dma_b(struct comedi_device *dev,
- struct s626_buffer_dma *pdma, size_t bsize)
-{
- struct pci_dev *pcidev = comedi_to_pci_dev(dev);
- void *vbptr;
- dma_addr_t vpptr;
-
- if (pdma == NULL)
- return;
-
- /* find the matching allocation from the board struct */
- vbptr = pdma->logical_base;
- vpptr = pdma->physical_base;
- if (vbptr) {
- pci_free_consistent(pcidev, bsize, vbptr, vpptr);
- pdma->logical_base = NULL;
- pdma->physical_base = 0;
- }
-}
-
static void s626_counters_init(struct comedi_device *dev)
{
int chan;
@@ -2527,6 +2507,24 @@ static int s626_allocate_dma_buffers(struct comedi_device *dev)
return 0;
}
+static void s626_free_dma_buffers(struct comedi_device *dev)
+{
+ struct pci_dev *pcidev = comedi_to_pci_dev(dev);
+ struct s626_private *devpriv = dev->private;
+
+ if (!devpriv)
+ return;
+
+ if (devpriv->rps_buf.logical_base)
+ pci_free_consistent(pcidev, S626_DMABUF_SIZE,
+ devpriv->rps_buf.logical_base,
+ devpriv->rps_buf.physical_base);
+ if (devpriv->ana_buf.logical_base)
+ pci_free_consistent(pcidev, S626_DMABUF_SIZE,
+ devpriv->ana_buf.logical_base,
+ devpriv->ana_buf.physical_base);
+}
+
static int s626_initialize(struct comedi_device *dev)
{
struct s626_private *devpriv = dev->private;
@@ -2923,11 +2921,6 @@ static void s626_detach(struct comedi_device *dev)
/* Close all interfaces on 7146 device */
writel(S626_MC1_SHUTDOWN, dev->mmio + S626_P_MC1);
writel(S626_ACON1_BASE, dev->mmio + S626_P_ACON1);
-
- s626_close_dma_b(dev, &devpriv->rps_buf,
- S626_DMABUF_SIZE);
- s626_close_dma_b(dev, &devpriv->ana_buf,
- S626_DMABUF_SIZE);
}
if (dev->irq)
@@ -2936,6 +2929,7 @@ static void s626_detach(struct comedi_device *dev)
iounmap(dev->mmio);
}
comedi_pci_disable(dev);
+ s626_free_dma_buffers(dev);
}
static struct comedi_driver s626_driver = {
--
2.0.3
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