On Wed, Sep 09, 2020 at 08:50:58PM +0530, Vaibhav Gupta wrote: > On Wed, Sep 09, 2020 at 08:23:32AM -0500, Bjorn Helgaas wrote: > > On Wed, Sep 09, 2020 at 03:33:15PM +0530, Vaibhav Gupta wrote: > > > On Tue, Sep 08, 2020 at 12:32:09PM -0500, Bjorn Helgaas wrote: > > > > On Mon, Jul 20, 2020 at 07:04:14PM +0530, Vaibhav Gupta wrote: > > > > > With legacy PM hooks, it was the responsibility of a driver to manage > > > > > PCI > > > > > states and also the device's power state. The generic approach is to > > > > > let > > > > > the PCI core handle the work. > > > > > > > > > > PCI core passes "struct device*" as an argument to the .suspend() and > > > > > .resume() callbacks. As the .suspend() work with "struct instance*", > > > > > extract it from "struct device*" using dev_get_drv_data(). > > > > > > > > > > Driver was also using PCI helper functions like > > > > > pci_save/restore_state(), > > > > > pci_disable/enable_device(), pci_set_power_state() and > > > > > pci_enable_wake(). > > > > > They should not be invoked by the driver. > > > > > > > > > > Compile-tested only. > > > > > > > > > > Signed-off-by: Vaibhav Gupta <[email protected]> > > > > > --- > > > > > drivers/scsi/megaraid/megaraid_sas_base.c | 61 > > > > > ++++++----------------- > > > > > 1 file changed, 16 insertions(+), 45 deletions(-) > > > > > > > > > > diff --git a/drivers/scsi/megaraid/megaraid_sas_base.c > > > > > b/drivers/scsi/megaraid/megaraid_sas_base.c > > > > > index 00668335c2af..4a6ee7778977 100644 > > > > > --- a/drivers/scsi/megaraid/megaraid_sas_base.c > > > > > +++ b/drivers/scsi/megaraid/megaraid_sas_base.c > > > > > @@ -7539,25 +7539,21 @@ static void > > > > > megasas_shutdown_controller(struct megasas_instance *instance, > > > > > megasas_return_cmd(instance, cmd); > > > > > } > > > > > > > > > > -#ifdef CONFIG_PM > > > > > /** > > > > > * megasas_suspend - driver suspend entry point > > > > > - * @pdev: PCI device structure > > > > > - * @state: PCI power state to suspend routine > > > > > + * @dev: Device structure > > > > > */ > > > > > -static int > > > > > -megasas_suspend(struct pci_dev *pdev, pm_message_t state) > > > > > +static int __maybe_unused > > > > > +megasas_suspend(struct device *dev) > > > > > { > > > > > - struct megasas_instance *instance; > > > > > - > > > > > - instance = pci_get_drvdata(pdev); > > > > > + struct megasas_instance *instance = dev_get_drvdata(dev); > > > > > > > > > > if (!instance) > > > > > return 0; > > > > > > > > > > instance->unload = 1; > > > > > > > > > > - dev_info(&pdev->dev, "%s is called\n", __func__); > > > > > + dev_info(dev, "%s is called\n", __func__); > > > > > > > > > > /* Shutdown SR-IOV heartbeat timer */ > > > > > if (instance->requestorId && > > > > > !instance->skip_heartbeat_timer_del) > > > > > @@ -7579,7 +7575,7 @@ megasas_suspend(struct pci_dev *pdev, > > > > > pm_message_t state) > > > > > > > > > > tasklet_kill(&instance->isr_tasklet); > > > > > > > > > > - pci_set_drvdata(instance->pdev, instance); > > > > > + dev_set_drvdata(dev, instance); > > > > > > > > It *might* be correct to replace "instance->pdev" with "dev", but it's > > > > not obvious and deserves some explanation. It's true that you can > > > > replace &pdev->dev with dev, but I don't know anything about > > > > instance->dev. > > > > Sorry, I meant "instance->pdev" here. > > > > > > I don't think this change is actually necessary, is it? > > > > "instance->pdev" is still a pci_dev pointer, so pci_set_drvdata() > > > > should work fine. ... > > > > > > > There is no instance->dev . The 'dev' passed dev_set_drvdata() is > > > same &pdev->dev. > > > > Yes, it's true that "dev" here is the same as the "&pdev->dev" we had > > previously. But we passed "instance->pdev" (not "pdev") to > > pci_set_drvdata(). So the question is whether instance->pdev->dev == > > dev. > > > > They *might* be the same, but I don't think it's obvious. > > > Yes, they are same. > driver/pci/pci-driver.c : > 'dev' is passed as parameter to both pci_device_probe() and pci_pm_suspend() > From 'dev', pci_device_probe() extracts "struct pci_dev*" and passes it to the > probe callback of this driver. > > In the proble function - megasas_probe_one() > :7347 instance->pdev = pdev; > :7386 pci_set_drvdata(pdev, instance); > > The proble function is using "struct pci_dev*" variable "pdev" provided by > core > and same we replaced &pdev->dev with "struct device *dev". > > So the instance->pdev->dev and 'dev' can only differ if 'dev' passed to > pci_device_probe() and pci_pm_suspend() are different.
OK. I think this requires too much analysis for this particular patch, which is really about deprecating pci_driver.suspend and .resume. We want patches to be easily verifiable with a minimum of extra research. I would completely support a separate patch to clean this up, though. The *ideal* thing would be to get rid of the set_drvdata() completely from the suspend routine. Doing it in the probe routine should be enough. > > > The dev pointer used here, points to same value. > > > > > > pci_get_drvdata() and pci_set_drvdata() invoke dev_get_drvdata() and > > > dev_set_drvdata() respectively. And they do nothing else. Seems like > > > additional unnecessary function calls and operations.
