@@ -1007,8 +1007,12 @@ static bool advk_pcie_valid_device(struct advk_pcie *pcie, struct pci_bus *bus,
return false;
/*
- * If the link goes down after we check for link-up, nothing bad
- * happens but the config access times out.
+ * If the link goes down after we check for link-up, we have a problem:
+ * if a PIO request is executed while link-down, the whole controller
+ * gets stuck in a non-functional state, and even after link comes up
+ * again, PIO requests won't work anymore, and a reset of the whole PCIe
+ * controller is needed. Therefore we need to prevent sending PIO
+ * requests while the link is down.
*/
if (!pci_is_root_bus(bus) && !advk_pcie_link_up(pcie))
return false;
Update the comment about what happens when link goes down after we have checked for link-up. If a PIO request is done while link-down, we have a serious problem. Signed-off-by: Marek Behún <kabel@kernel.org> --- drivers/pci/controller/pci-aardvark.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)