On Thu, Oct 24, 2019 at 12:38:03PM +0300, Mika Westerberg wrote: > On Wed, Oct 23, 2019 at 10:52:53AM +0300, Mika Westerberg wrote: > > > Shouldn't we check for slot_status being an error response (~0) > > > instead of looking for PCIBIOS_DEVICE_NOT_FOUND? There are 7 RsvdP > > > bits in Slot Status, so ~0 is not a valid value for the register. > > > > > > All 16 bits of Link Status are defined, but ~0 is still an invalid > > > value because the Current Link Speed and Negotiated Link Width fields > > > only define a few valid encodings. > > > > Indeed that's a good point. I'll try that. > > Just checking if I understand correctly what you are suggesting. > > Currently we use pcie_capability_read_word() and check the return value. > If the device is gone it returns an error and resets *val to 0. That > only works if pci_dev_is_disconnected() is true so we would need to do > something like below. > > pciehp_check_link_active(): > > ret = pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status); > if (ret == PCIBIOS_DEVICE_NOT_FOUND || lnk_status == (u16)~0) > return -ENODEV; Yes, I guess this is what you'd have to do. > Or you mean that we check only for ~0 in which case we either need to > use pci_read_config_word() directly here or modify pcie_capability_read_word() > return ~0 instead of clearing it? I *would* like to explore removing the "*val = 0" code from pci_capability_read*(), but not in the context of this issue.
