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

From: Kok, Auke
Date: Mon Dec 17 2007 - 17:11:54 EST


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@xxxxxxxxxxxxxxxxxxxx>

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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