Message-ID: <be2a1cce5691e5dc7fb875f46d5f2085b6a55542.camel@linux.intel.com>
Date:   Tue, 21 Dec 2021 10:16:36 -0800
From:   "David E. Box" <david.e.box@...ux.intel.com>
To:     Hans de Goede <hdegoede@...hat.com>,
        Greg KH <gregkh@...uxfoundation.org>
Cc:     lee.jones@...aro.org, 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 Tue, 2021-12-21 at 18:04 +0100, Hans de Goede wrote:
> Hi,
> 
> On 12/21/21 17:54, Greg KH wrote:
> > On Tue, Dec 21, 2021 at 08:44:57AM -0800, David E. Box wrote:
> > > On Tue, 2021-12-21 at 08:38 +0100, Greg KH wrote:
> > > > On Wed, Dec 08, 2021 at 01:30:06PM -0800, David E. Box wrote:
> > > > > On Wed, 2021-12-08 at 20:21 +0100, Greg KH wrote:
> > > > > > On Wed, Dec 08, 2021 at 11:09:48AM -0800, David E. Box wrote:
> > > > > > > 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)
> > > > > > 
> > > > > > Wow that is opaque.  Why not do it on remove instead?
> > > > > 
> > > > > This code is common for auxdev cleanup. AFAICT most auxiliary bus code
> > > > > is
> > > > > done by drivers that have
> > > > > some other primary function. They clean up their primary function
> > > > > resources
> > > > > in remove, but they
> > > > > clean up the auxdev using the method above. In this case the sole
> > > > > purpose of
> > > > > this driver is to
> > > > > create the auxdev. There are no other resources beyond what the auxdev
> > > > > is
> > > > > using.
> > > > > 
> > > > > Adding runtime pm to the pci driver will change this. Remove will be
> > > > > needed
> > > > > then.
> > > > 
> > > > And who will notice that being required when that happens?
> > > > 
> > > > Why is there no runtime PM for this driver?  Do you not care about power
> > > > consumption?  :)
> > > 
> > > Of course. :)
> > > 
> > > There's a backlog of patches waiting for this series. One adds support for
> > > the
> > > telemetry device (an auxdev) on the DG2 GPU. This device requires runtime
> > > pm in
> > > order for the slot to go D3. But this also requires changes to the
> > > telemetry
> > > driver in order for runtime pm to be handled correctly. These and other
> > > patches,
> > > including a series to have all current aux drivers use the new drvdata
> > > helpers,
> > > are waiting for this.
> > 
> > I can take the aux driver drvdata patch now, through my tree, if you
> > want, no need to make it wait for this tiny driver.
> > 
> > Feel free to send it independant of the existing patchset, and with the
> > cleanup patches at the same time, should be quite easy to get merged.
> 
> If you're going to take that one, can you perhaps take patches
> 1-3 for 5.17 through your tree as well (patch 3 depends on 2/it) ?
> 
> Note there is a v4 of this series, see please use that :)
> 
> I assume the follow up patches are also going to need patch 3
> (the actual conversion of the driver to aux-bus).

Yes.

> 
> Here is my Ack for the pdx86 bits in patch 3:
> 
> Acked-by: Hans de Goede <hdegoede@...hat.com>
> 
> And patch 1 and 3 also have acks from the PCI resp. MFD subsys maintainers,
> so I guess taking this all upstream through your tree is fine.

Should I send 1-3 plus the drvdata cleanup patches I have to Grep? V5?

> 
> That leaves patches 4-6, 4 is the patching adding the new
> "Intel Software Defined Silicon driver" sysfs API and I would
> like to take some time to thoroughly review the new
> userspace API, which I don't see happening before the
> Christmas Holidays, so I don't plan to merge 4-6 (which
> depends on 3) until after 5.17-rc1.

Understood. Thanks.

> 
> Regards,
> 
> Hans
> 

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