[+Rafael] On Sun, Feb 20, 2022 at 08:33:44PM +0100, Marek Behún wrote: > From: Miquel Raynal <miquel.raynal@xxxxxxxxxxx> > > Add suspend and resume callbacks. The priority of these are > "_noirq()", to workaround early access to the registers done by the > PCI core through the ->read()/->write() callbacks at resume time. This commit log should be rewritten to clarify it. IIUC, you are hooking up the _noirq() callbacks to take advantage of callbacks ordering rather than needing the IRQ disabled per-se. Thread here: https://lore.kernel.org/linux-pci/20220220193346.23789-17-kabel@xxxxxxxxxx I'd ask Rafael please if this is common practice or a workaround and whether that's how it should be done. Thanks, Lorenzo > Signed-off-by: Miquel Raynal <miquel.raynal@xxxxxxxxxxx> > Signed-off-by: Pali Rohár <pali@xxxxxxxxxx> > Signed-off-by: Marek Behún <kabel@xxxxxxxxxx> > --- > drivers/pci/controller/pci-aardvark.c | 39 +++++++++++++++++++++++++++ > 1 file changed, 39 insertions(+) > > diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c > index 3b51f47abd72..8c9ac7766ac7 100644 > --- a/drivers/pci/controller/pci-aardvark.c > +++ b/drivers/pci/controller/pci-aardvark.c > @@ -1896,6 +1896,44 @@ static int advk_pcie_setup_phy(struct advk_pcie *pcie) > return ret; > } > > +static int __maybe_unused advk_pcie_suspend(struct device *dev) > +{ > + struct advk_pcie *pcie = dev_get_drvdata(dev); > + > + advk_pcie_disable_phy(pcie); > + > + clk_disable_unprepare(pcie->clk); > + > + return 0; > +} > + > +static int __maybe_unused advk_pcie_resume(struct device *dev) > +{ > + struct advk_pcie *pcie = dev_get_drvdata(dev); > + int ret; > + > + ret = clk_prepare_enable(pcie->clk); > + if (ret) > + return ret; > + > + ret = advk_pcie_enable_phy(pcie); > + if (ret) > + return ret; > + > + advk_pcie_setup_hw(pcie); > + > + return 0; > +} > + > +/* > + * The PCI core will try to reconfigure the bus quite early in the resume path. > + * We must use the _noirq() alternatives to ensure the controller is ready when > + * the core uses the ->read()/->write() callbacks. > + */ > +static const struct dev_pm_ops advk_pcie_dev_pm_ops = { > + SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(advk_pcie_suspend, advk_pcie_resume) > +}; > + > static int advk_pcie_probe(struct platform_device *pdev) > { > struct device *dev = &pdev->dev; > @@ -2171,6 +2209,7 @@ static struct platform_driver advk_pcie_driver = { > .driver = { > .name = "advk-pcie", > .of_match_table = advk_pcie_of_match_table, > + .pm = &advk_pcie_dev_pm_ops, > }, > .probe = advk_pcie_probe, > .remove = advk_pcie_remove, > -- > 2.34.1 >
