[PATCH] PCI: fix for quirk_e100_interrupt()

[PATCH] PCI: fix for quirk_e100_interrupt()

[Ivan Kokshaysky]

Check that the e100 is in the D0 power state. If it's not, it won't
respond to MMIO accesses and we end up with master-abort machine
checks on some platforms.

Signed-off-by: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
---
 drivers/pci/quirks.c |   14 +++++++++++++-
 1 files changed, 13 insertions(+), 1 deletions(-)

diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 26cc4dc..c8b2b9d 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -1406,9 +1406,10 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_NETMOS, PCI_ANY_ID, quirk_netmos);
 
 static void __devinit quirk_e100_interrupt(struct pci_dev *dev)
 {
-	u16 command;
+	u16 command, pmcsr;
 	u8 __iomem *csr;
 	u8 cmd_hi;
+	int pm;
 
 	switch (dev->device) {
 	/* PCI IDs taken from drivers/net/e100.c */
@@ -1442,6 +1443,17 @@ static void __devinit quirk_e100_interrupt(struct pci_dev *dev)
 	if (!(command & PCI_COMMAND_MEMORY) || !pci_resource_start(dev, 0))
 		return;
 
+	/*
+	 * Check that the device is in the D0 power state. If it's not,
+	 * there is no point to look any further.
+	 */
+	pm = pci_find_capability(dev, PCI_CAP_ID_PM);
+	if (pm) {
+		pci_read_config_word(dev, pm + PCI_PM_CTRL, &pmcsr);
+		if ((pmcsr & PCI_PM_CTRL_STATE_MASK) != PCI_D0)
+			return;
+	}
+
 	/* Convert from PCI bus to resource space.  */
 	csr = ioremap(pci_resource_start(dev, 0), 8);
 	if (!csr) {

Re: [PATCH] PCI: fix for quirk_e100_interrupt()

[Kok, Auke]

Ivan Kokshaysky wrote:
> Check that the e100 is in the D0 power state. If it's not, it won't
> respond to MMIO accesses and we end up with master-abort machine
> checks on some platforms.
> 
> Signed-off-by: Ivan Kokshaysky <ink@jurassic.park.msu.ru>

what kind of platform actually is doing this? It almost seems like something is
wrong with that platform's BIOS and I wonder if this workaround should not be more
general (IOW is it not just e100 that is affected but other components as well?)

Auke


> ---
>  drivers/pci/quirks.c |   14 +++++++++++++-
>  1 files changed, 13 insertions(+), 1 deletions(-)
> 
> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
> index 26cc4dc..c8b2b9d 100644
> --- a/drivers/pci/quirks.c
> +++ b/drivers/pci/quirks.c
> @@ -1406,9 +1406,10 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_NETMOS, PCI_ANY_ID, quirk_netmos);
>  
>  static void __devinit quirk_e100_interrupt(struct pci_dev *dev)
>  {
> -	u16 command;
> +	u16 command, pmcsr;
>  	u8 __iomem *csr;
>  	u8 cmd_hi;
> +	int pm;
>  
>  	switch (dev->device) {
>  	/* PCI IDs taken from drivers/net/e100.c */
> @@ -1442,6 +1443,17 @@ static void __devinit quirk_e100_interrupt(struct pci_dev *dev)
>  	if (!(command & PCI_COMMAND_MEMORY) || !pci_resource_start(dev, 0))
>  		return;
>  
> +	/*
> +	 * Check that the device is in the D0 power state. If it's not,
> +	 * there is no point to look any further.
> +	 */
> +	pm = pci_find_capability(dev, PCI_CAP_ID_PM);
> +	if (pm) {
> +		pci_read_config_word(dev, pm + PCI_PM_CTRL, &pmcsr);
> +		if ((pmcsr & PCI_PM_CTRL_STATE_MASK) != PCI_D0)
> +			return;
> +	}
> +
>  	/* Convert from PCI bus to resource space.  */
>  	csr = ioremap(pci_resource_start(dev, 0), 8);
>  	if (!csr) {
> --
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Re: [PATCH] PCI: fix for quirk_e100_interrupt()

[Ivan Kokshaysky]

On Mon, Dec 17, 2007 at 01:57:33PM -0800, Kok, Auke wrote:
> what kind of platform actually is doing this? It almost seems like something is
> wrong with that platform's BIOS and I wonder if this workaround should not be more
> general (IOW is it not just e100 that is affected but other components as well?)

It's alpha sx164. But I don't think the firmware does anything wrong here,
it just put e100 in "sleep" or "soft off" state.
I think a general rule is that you cannot access device MEM or IO registers
without pci_enable_device first (or making sure that the device is actually
enabled in other ways).

Ivan.