From: Jian-Hong Pan Date: Tue, 1 Oct 2024 08:34:40 +0000 (+0800) Subject: PCI/ASPM: Add notes about enabling PCI-PM L1SS to pci_enable_link_state(_locked) X-Git-Tag: microblaze-v6.16~472^2~32^2~1 X-Git-Url: http://git.monstr.eu/?a=commitdiff_plain;h=e1714f3b1f4d2af5df26e4a0e4a70ef64b15e3ee;p=linux-2.6-microblaze.git PCI/ASPM: Add notes about enabling PCI-PM L1SS to pci_enable_link_state(_locked) According to "PCIe r6.0, sec 5.5.4", add note about D0 requirement in pci_enable_link_state() kernel-doc. Link: https://lore.kernel.org/r/20241001083438.10070-6-jhp@endlessos.org Signed-off-by: Jian-Hong Pan Signed-off-by: Krzysztof Wilczyński Reviewed-by: Kuppuswamy Sathyanarayanan Acked-by: Bjorn Helgaas --- diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index e943691bc931..28567d457613 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -1450,6 +1450,9 @@ static int __pci_enable_link_state(struct pci_dev *pdev, int state, bool locked) * touch the LNKCTL register. Also note that this does not enable states * disabled by pci_disable_link_state(). Return 0 or a negative errno. * + * Note: Ensure devices are in D0 before enabling PCI-PM L1 PM Substates, per + * PCIe r6.0, sec 5.5.4. + * * @pdev: PCI device * @state: Mask of ASPM link states to enable */ @@ -1466,6 +1469,9 @@ EXPORT_SYMBOL(pci_enable_link_state); * can't touch the LNKCTL register. Also note that this does not enable states * disabled by pci_disable_link_state(). Return 0 or a negative errno. * + * Note: Ensure devices are in D0 before enabling PCI-PM L1 PM Substates, per + * PCIe r6.0, sec 5.5.4. + * * @pdev: PCI device * @state: Mask of ASPM link states to enable *