Messages in this thread | | | Date | Mon, 2 Oct 2017 17:14:09 -0700 | From | Govindarajulu Varadarajan <> | Subject | Re: [PATCH V2] PCI: AER: fix deadlock in do_recovery |
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On Sun, 1 Oct 2017, Christoph Hellwig wrote:
>> +struct aer_device_list { >> + struct device *dev; >> + struct hlist_node node; >> +}; >> + >> extern struct bus_type pcie_port_bus_type; >> void aer_isr(struct work_struct *work); >> void aer_print_error(struct pci_dev *dev, struct aer_err_info *info); >> diff --git a/drivers/pci/pcie/aer/aerdrv_core.c b/drivers/pci/pcie/aer/aerdrv_core.c >> index 890efcc574cb..d524f2c2c288 100644 >> --- a/drivers/pci/pcie/aer/aerdrv_core.c >> +++ b/drivers/pci/pcie/aer/aerdrv_core.c >> @@ -346,6 +346,47 @@ static int report_resume(struct pci_dev *dev, void *data) >> return 0; >> } >> >> +int aer_get_pci_dev(struct pci_dev *pdev, void *data) >> +{ >> + struct hlist_head *hhead = (struct hlist_head *)data; >> + struct device *dev = &pdev->dev; >> + struct aer_device_list *entry; >> + >> + entry = kmalloc(sizeof(*entry), GFP_KERNEL); >> + if (!entry) >> + /* continue with other devices, lets not return error */ >> + return 0; >> + >> + entry->dev = get_device(dev); >> + hlist_add_head(&entry->node, hhead); >> + >> + return 0; > > Can we just embedded the list_head in the pci_dev? Or is there a way > we can have multiple chains like this pending at the same time? >
I would avoid increasing the size of pci_dev. The list_head would be empty after we call aer_pci_walk_bus(). We already have pci_bus *subordinate to link all the 'device's. Making list_head available to others would require a lock. I would avoid that.
>> +static void aer_pci_walk_bus(struct pci_bus *top, >> + int (*cb)(struct pci_dev *, void *), >> + struct aer_broadcast_data *result) >> +{ >> + HLIST_HEAD(dev_hlist); >> + struct hlist_node *tmp; >> + struct aer_device_list *entry; > > Do we want to offer this as generic PCIe functionality? If not we can > probably hardcode the callback and callback data to simplify this a lot. >
I could not find any other code which aquires device_lock in pci_walk_bus cb function. Can you tell me how we can hardcore callback and callback data here?
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