Since a 64-bit BAR consists of a BAR pair, and since there is no BAR after BAR_5, BAR_5 cannot be 64-bits wide. This sanity check is done in pci_epc_clear_bar(), so that we don't need to do this sanity check in all epc->ops->clear_bar() implementations. Signed-off-by: Niklas Cassel <niklas.cassel@xxxxxxxx> --- Kishon made a review comment that he wanted this: https://marc.info/?l=linux-kernel&m=152161168226203 Personally, I don't think that this check is needed, since pci_epc_set_bar() already does this check, and no one should modify the flags after pci_epc_set_bar() has been called. If everyone agrees, then this patch could be dropped. drivers/pci/endpoint/pci-epc-core.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c index eccc942043cb..b0ee42739c3c 100644 --- a/drivers/pci/endpoint/pci-epc-core.c +++ b/drivers/pci/endpoint/pci-epc-core.c @@ -285,7 +285,9 @@ void pci_epc_clear_bar(struct pci_epc *epc, u8 func_no, { unsigned long flags; - if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions) + if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions || + (epf_bar->barno == BAR_5 && + epf_bar->flags & PCI_BASE_ADDRESS_MEM_TYPE_64)) return; if (!epc->ops->clear_bar) -- 2.14.2
