Hi guys, On 08/03/17 23:08, Rajat Jain wrote: > On Wed, Mar 8, 2017 at 2:39 PM, Bjorn Helgaas <helgaas@xxxxxxxxxx> wrote: >> On Wed, Mar 08, 2017 at 06:44:36PM +0000, James Morse wrote: >>> On 03/01/17 06:34, Rajat Jain wrote: >>>> Add code to actually configure the L1 substate settigns on the >>>> upstream and downstream device, while taking care of the rules >>>> dictated by the PCIe spec. >>> >>> While testing hibernate on an arm64 juno with v4.11-rc1, I get a NULL >> pointer >>> dereference from pcie_config_aspm_link(): >>> >>> >>>> diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c >>>> index a70afdf..6735f38 100644 >>>> --- a/drivers/pci/pcie/aspm.c >>>> +++ b/drivers/pci/pcie/aspm.c >>>> @@ -597,11 +683,23 @@ static void pcie_config_aspm_dev(struct pci_dev >> *pdev, u32 val) >>>> static void pcie_config_aspm_link(struct pcie_link_state *link, u32 >> state) >>>> { >>>> u32 upstream = 0, dwstream = 0; >>>> - struct pci_dev *child, *parent = link->pdev; >>>> + struct pci_dev *child = link->downstream, *parent = link->pdev; >>> >>> >>> Here link->downstream is NULL, >> >> Sorry about the breakage. Can you try also cherry-picking this >> commit: >> >> https://git.kernel.org/cgit/linux/kernel/git/helgaas/pci. >> git/commit/?h=for-linus&id=3bd7db63a841e8c5297bb18ad801df67d5e38ad2 >> >> Yinghai tripped over a similar problem in a different way, but I >> suspect his fix might also fix the problem you're seeing. >> > > Yes, I think that should fix it. Yes, this fixes the problem. Thanks! I should have dug through the list a little more to see if there was an existing fix... Thanks, James