On Mon, May 25, 2015 at 09:34:33AM +0800, Yijing Wang wrote: > https://bugzilla.kernel.org/show_bug.cgi?id=94361 reported > in ATCA platform, system had unusual pcie topology: > > (root port) (downstream port) (upstream port) > +-1c.0-[02-0a]----00.0-[03-0a]--+-00.0-[04]-- > | +-01.0-[05]-- (downstream port) > | +-02.0-[06]-- > | +-03.0-[07]-- > | +-08.0-[08]-- > | +-09.0-[09]-- > | \-0a.0-[0a]-- > We assumed root port and downstream port always > have external link, and downstream port always has a > upstream port. So in this case, when we allocated > pcie_link_state for downstream port 02:00.0, it try > to get parent bus pcie_link_state, > parent = pdev->bus->parent->self->link_state; > because root bus self is NULL, system will crash here. > > Use pdev->has_secondary_link(introduced in previous patch) > to fix this issue. > > Signed-off-by: Yijing Wang <wangyijing@xxxxxxxxxx> Applied to pci/aspm for v4.2, thanks! It's easier if: - You include a [0/3] cover letter. Then I can respond once there to say I've applied the series. - You post a complete v5 instead of an "[Update][PATCH v4 2/3]". In this case, with only three patches and no further iterations, it's not a big deal, but it does make it harder for me to make sure I have the right version of everything. Bjorn > --- > drivers/pci/pcie/aspm.c | 9 ++++----- > 1 files changed, 4 insertions(+), 5 deletions(-) > > diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c > index 4e1af76..942bf97 100644 > --- a/drivers/pci/pcie/aspm.c > +++ b/drivers/pci/pcie/aspm.c > @@ -525,7 +525,7 @@ static struct pcie_link_state *alloc_pcie_link_state(struct pci_dev *pdev) > INIT_LIST_HEAD(&link->children); > INIT_LIST_HEAD(&link->link); > link->pdev = pdev; > - if (pci_pcie_type(pdev) == PCI_EXP_TYPE_DOWNSTREAM) { > + if (pci_pcie_type(pdev) != PCI_EXP_TYPE_ROOT_PORT) { > struct pcie_link_state *parent; > parent = pdev->bus->parent->self->link_state; > if (!parent) { > @@ -561,8 +561,8 @@ void pcie_aspm_init_link_state(struct pci_dev *pdev) > > if (!pci_is_pcie(pdev) || pdev->link_state) > return; > - if (pci_pcie_type(pdev) != PCI_EXP_TYPE_ROOT_PORT && > - pci_pcie_type(pdev) != PCI_EXP_TYPE_DOWNSTREAM) > + > + if (!pdev->has_secondary_link) > return; > > /* VIA has a strange chipset, root port is under a bridge */ > @@ -715,8 +715,7 @@ static void __pci_disable_link_state(struct pci_dev *pdev, int state, bool sem) > if (!pci_is_pcie(pdev)) > return; > > - if (pci_pcie_type(pdev) == PCI_EXP_TYPE_ROOT_PORT || > - pci_pcie_type(pdev) == PCI_EXP_TYPE_DOWNSTREAM) > + if (pdev->has_secondary_link) > parent = pdev; > if (!parent || !parent->link_state) > return; > -- > 1.7.1 > > -- > 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 -- 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
