On Tue, Oct 06, 2020 at 01:24:28PM -0500, Sanjay R Mehta wrote: > if DL_ACTIVE bit is set it means that there is no need to check > PCI_EXP_LNKSTA_LT bit, as DL_ACTIVE would have set only if the link > is already trained. Hence adding a check which takes care of this > scenario.
Sorry for being dense but I don't understand this at all: The PCI_EXP_DPC_CAP_DL_ACTIVE bit which you check here indicates that the port is capable of sending an ERR_COR interrupt whenever the link transitions from inactive to active. What is the connection to the PCI_EXP_LNKSTA_LT bit (which indicates that the link is still being trained)? Also, the negation of a bitwise AND is always either 0 or 1 (!(lnk_status & PCI_EXP_DPC_CAP_DL_ACTIVE)), so bit 0 is set or not set. However PCI_EXP_LNKSTA_LT is bit 11. A bitwise AND of bit 11 and 0 is always 0, so the expression can never be 1. Am I missing something? Thanks, Lukas > Signed-off-by: Sanjay R Mehta <sanju.me...@amd.com> > --- > drivers/pci/hotplug/pciehp_hpc.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/pci/hotplug/pciehp_hpc.c > b/drivers/pci/hotplug/pciehp_hpc.c > index 53433b3..81d1348 100644 > --- a/drivers/pci/hotplug/pciehp_hpc.c > +++ b/drivers/pci/hotplug/pciehp_hpc.c > @@ -309,7 +309,8 @@ int pciehp_check_link_status(struct controller *ctrl) > > pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status); > ctrl_dbg(ctrl, "%s: lnk_status = %x\n", __func__, lnk_status); > - if ((lnk_status & PCI_EXP_LNKSTA_LT) || > + if (((lnk_status & PCI_EXP_LNKSTA_LT) & > + !(lnk_status & PCI_EXP_DPC_CAP_DL_ACTIVE)) || > !(lnk_status & PCI_EXP_LNKSTA_NLW)) { > ctrl_err(ctrl, "link training error: status %#06x\n", > lnk_status); > -- > 2.7.4