diff options
| author | Marek Behún <kabel@kernel.org> | 2022-05-04 18:57:55 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-05-12 12:30:34 +0200 |
| commit | 4b4f9f172af402d4d4c01cc63d77d115af637d32 (patch) | |
| tree | 4771152aa06f10dbb021e9f942fb55e7afdc9a2f | |
| parent | 0dde2c7e6afbee833d7f355702c43b91007b9784 (diff) | |
PCI: aardvark: Update comment about link going down after link-up
commit 92f4ffecc4170ce29e67a1f8d51c168c3de95fb2 upstream.
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: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/pci/controller/pci-aardvark.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c index 669663fb982e..ff45052cf48d 100644 --- a/drivers/pci/controller/pci-aardvark.c +++ b/drivers/pci/controller/pci-aardvark.c @@ -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; |