linux-kernel - Re: [PATCH RESEND V2 3/6] platform/x86/intel: Move intel

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Message-ID: <a70956e1c4da10603e29087e893cbae62ce82631.camel@linux.intel.com>
Date:   Wed, 08 Dec 2021 11:09:48 -0800
From:   "David E. Box" <david.e.box@...ux.intel.com>
To:     Greg KH <gregkh@...uxfoundation.org>
Cc:     lee.jones@...aro.org, hdegoede@...hat.com, bhelgaas@...gle.com,
        andriy.shevchenko@...ux.intel.com, srinivas.pandruvada@...el.com,
        mgross@...ux.intel.com, linux-kernel@...r.kernel.org,
        platform-driver-x86@...r.kernel.org, linux-pci@...r.kernel.org,
        Mark Gross <markgross@...nel.org>
Subject: Re: [PATCH RESEND V2 3/6] platform/x86/intel: Move intel_pmt from
 MFD to Auxiliary Bus

On Wed, 2021-12-08 at 19:11 +0100, Greg KH wrote:
> On Wed, Dec 08, 2021 at 09:47:26AM -0800, David E. Box wrote:
> > On Wed, 2021-12-08 at 17:22 +0100, Greg KH wrote:
> > > On Tue, Dec 07, 2021 at 05:50:12PM -0800, David E. Box wrote:
> > > > +static struct pci_driver intel_vsec_pci_driver = {
> > > > +       .name = "intel_vsec",
> > > > +       .id_table = intel_vsec_pci_ids,
> > > > +       .probe = intel_vsec_pci_probe,
> > > > +};
> > > 
> > > So when the PCI device is removed from the system you leak resources and
> > > have dangling devices?
> > 
> > No.
> > 
> > > 
> > > Why no PCI remove driver callback?
> > 
> > After probe all resources are device managed. There's nothing to explicitly clean up. When the
> > PCI
> > device is removed, all aux devices are automatically removed. This is the case for the SDSi
> > driver
> > as well.
> 
> Where is the "automatic cleanup" happening?  As this pci driver is bound
> to the PCI device, when the device is removed, what is called in this
> driver to remove the resources allocated in the probe callback?
> 
> confused,

devm_add_action_or_reset(&pdev->dev, intel_vsec_remove_aux, auxdev)

intel_vsec_remove_aux() gets called when the PCI device is removed. It calls auxiliary_device_unit()
which in turn calls the auxdev release() function that cleans up resources.

When the auxdev is removed, all resources that were dev_m added by the SDSi driver are released too
which is why it has no remove() either. I'll add the tests that check this.

David

> 
> greg k-h