On Sat, Jul 05, 2014 at 10:27:08AM -0600, Bjorn Helgaas wrote:
> On Thu, Jun 19, 2014 at 07:58:16PM +0800, Guo Chao wrote:
> > Commit bd064f0a sets IORESOURCE_UNSET flag if resources can not be
> > assgined. Part of these changes breaks resource assignment.
> >
> > If resource is too big, PCI core assgins basic part first and
> > extends (reassigns) it to include optional part (notably SR-IOV resources).
> > In this case, IORESOURCE_UNSET should not be set if resource is properly
> > assigned before reassigning. Otherwise, these resources are never updated
> > to hardware and we will see errors like this:
> >
> > pci 0003:00:00.0: can't enable device: BAR 15 [mem size 0x0c000000 64bit pref] not assigned
> > pci 0003:00:00.0: Error enabling bridge (-22), continuing
> >
> > Signed-off-by: Guo Chao <yan@xxxxxxxxxxxxxxxxxx>
>
> I propose the following simpler patch. Can you verify that it works for
> you?
Hi Bjorn:
Sure it works.
(Sorry for this late response. The machine is out of reach for
past few days.)
Thanks,
Guo Chao
>
>
> commit 57ece376a3b9e013277032f473197052f1144142
> Author: Guo Chao <yan@xxxxxxxxxxxxxxxxxx>
> Date: Thu Jul 3 18:30:29 2014 -0600
>
> PCI: Keep original resource if we fail to expand it
>
> If we have space assigned to a resource, we try to expand the resource
> (e.g., to accommodate SR-IOV resources), and the expansion attempt fails,
> we should keep the original assignment.
>
> After bd064f0a231a ("PCI: Mark resources as IORESOURCE_UNSET if we can't
> assign them"), we left the resource marked IORESOURCE_UNSET when the
> expansion failed, even if it had originally been set. That caused errors
> like this:
>
> pci 0003:00:00.0: can't enable device: BAR 15 [mem size 0x0c000000 64bit pref] not assigned
> pci 0003:00:00.0: Error enabling bridge (-22), continuing
>
> Fix this by restoring the original flags when reassignment fails.
>
> [bhelgaas: reworked to simplify, changelog]
> Fixes: bd064f0a231a ("PCI: Mark resources as IORESOURCE_UNSET if we can't assign them")
> Signed-off-by: Guo Chao <yan@xxxxxxxxxxxxxxxxxx>
> Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> CC: stable@xxxxxxxxxxxxxxx # v3.15+
>
> diff --git a/drivers/pci/setup-res.c b/drivers/pci/setup-res.c
> index caed1ce6facd..9faebcfeec4d 100644
> --- a/drivers/pci/setup-res.c
> +++ b/drivers/pci/setup-res.c
> @@ -320,9 +320,11 @@ int pci_reassign_resource(struct pci_dev *dev, int resno, resource_size_t addsiz
> resource_size_t min_align)
> {
> struct resource *res = dev->resource + resno;
> + unsigned long flags;
> resource_size_t new_size;
> int ret;
>
> + flags = res->flags;
> res->flags |= IORESOURCE_UNSET;
> if (!res->parent) {
> dev_info(&dev->dev, "BAR %d: can't reassign an unassigned resource %pR\n",
> @@ -339,7 +341,12 @@ int pci_reassign_resource(struct pci_dev *dev, int resno, resource_size_t addsiz
> dev_info(&dev->dev, "BAR %d: reassigned %pR\n", resno, res);
> if (resno < PCI_BRIDGE_RESOURCES)
> pci_update_resource(dev, resno);
> + } else {
> + res->flags = flags;
> + dev_info(&dev->dev, "BAR %d: %pR (failed to expand by %#llx)\n",
> + resno, res, addsize);
> }
> +
> return ret;
> }
>
>
--
To unsubscribe from this list: send the line "unsubscribe linux-pci" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
