Commit 92f4ffec authored by Marek Behún's avatar Marek Behún Committed by Lorenzo Pieralisi
Browse files

PCI: aardvark: Update comment about link going down after link-up 

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.

Link: https://lore.kernel.org/r/20220110015018.26359-23-kabel@kernel.org


Signed-off-by: default avatarMarek Behún <kabel@kernel.org>
Signed-off-by: default avatarLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
parent 0c36ab43

drivers/pci/controller/pci-aardvark.c

+6 −2
Original line number Diff line number Diff line
@@ -998,8 +998,12 @@ 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;