On 09/04/2015 06:14 PM, Frank Rowand wrote:
On 9/4/2015 12:12 PM, David Daney wrote:
From: David Daney <david.da...@cavium.com>
It is perfectly legitimate for a PCI device to have an
PCI_INTERRUPT_PIN value of zero. This happens if the device doesn't
use interrupts, or on PCIe devices, where only MSI/MSI-X are
supported.
Silence the annoying "of_irq_parse_pci() failed with rc=-19" error
messages by making them conditional on !-ENODEV (which can only be
produced in the PCI_INTERRUPT_PIN == 0 case).
Signed-off-by: David Daney <david.da...@cavium.com>
---
drivers/of/of_pci_irq.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/of/of_pci_irq.c b/drivers/of/of_pci_irq.c
index 1710d9d..33d242a 100644
--- a/drivers/of/of_pci_irq.c
+++ b/drivers/of/of_pci_irq.c
@@ -106,7 +106,9 @@ int of_irq_parse_and_map_pci(const struct pci_dev *dev, u8
slot, u8 pin)
ret = of_irq_parse_pci(dev, &oirq);
if (ret) {
- dev_err(&dev->dev, "of_irq_parse_pci() failed with rc=%d\n",
ret);
+ if (ret != -ENODEV)
+ dev_err(&dev->dev,
+ "of_irq_parse_pci() failed with rc=%d\n", ret);
return 0; /* Proper return code 0 == NO_IRQ */
}
It is not safe to assume that the functions that of_irq_parse_pci() calls
will never be modified to return -ENODEV, thus resulting in of_irq_parse_pci()
returning -ENODEV for a reason other than PCI_INTERRUPT_PIN == 0.
Since the current implementation *only ever* returns -ENODEV for
PCI_INTERRUPT_PIN == 0, we could just document that behavior, and not
hack up the APIs by adding a second return channel from the function.
The additional change on top of my patch would be to add a comment
describing this behavior.
David Daney.
A more robust solution would be something like:
(1) Change of_irq_parse_pci() to _of_irq_parse_pci(), adding an argument and
use it to report the case of PCI_INTERRUPT_PIN == 0.
static int _of_irq_parse_pci(const struct pci_dev *pdev, struct of_phandle_args
*out_irq, int *no_pin)
{
...
*no_pin = 0;
...
/* No pin, exit */
if (pin == 0) {
*no_pin = 1;
return -ENODEV;
}
...
int of_irq_parse_pci(const struct pci_dev *pdev, struct of_phandle_args
*out_irq)
{
int no_pin;
return _of_irq_parse_pci(pdev, out_irq, &no_pin)
}
(2) Then the fix to of_irq_parse_and_map_pci() would be:
+ int no_pin;
ret = of_irq_parse_pci(dev, &oirq, &no_pin);
if (ret) {
- dev_err(&dev->dev, "of_irq_parse_pci() failed with rc=%d\n",
ret);
+ if (!no_pin)
+ dev_err(&dev->dev,
+ "of_irq_parse_pci() failed with rc=%d\n", ret);
return 0; /* Proper return code 0 == NO_IRQ */
}
I'm not sure I like my solution, there might be a better way.
I also noticed another bug while looking at of_irq_parse_pci(). It returns
the non-zero return value from pci_read_config_byte(). But that value is
one of the PCI function error values from include/linux/pci.h, such as:
#define PCIBIOS_BAD_REGISTER_NUMBER 0x87
instead of a negative errno.
-Frank
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