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| author | Marek Behún <kabel@kernel.org> | 2022-01-10 02:50:17 +0100 |
|---|---|---|
| committer | Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> | 2022-02-08 11:45:58 +0100 |
| commit | 92f4ffecc4170ce29e67a1f8d51c168c3de95fb2 (patch) | |
| tree | f8c5e12eae8c3d1286dbc525d5f2af18f1db9f87 /drivers/pci/controller/pci-aardvark.c | |
| parent | PCI: aardvark: Drop __maybe_unused from advk_pcie_disable_phy() (diff) | |
| download | linux-92f4ffecc4170ce29e67a1f8d51c168c3de95fb2.tar.xz linux-92f4ffecc4170ce29e67a1f8d51c168c3de95fb2.zip | |
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: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Diffstat (limited to 'drivers/pci/controller/pci-aardvark.c')
| -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 3cbaffe892a4..5be382b19d9a 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; |