Re: [PATCH v2 2/7] PCI: ACPI: PM: Do not use pci_platform_pm_ops for ACPI

From: Ferry Toth <fntoth@gmail.com>
To: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>,
	Linux PCI <linux-pci@vger.kernel.org>,
	Linux ACPI <linux-acpi@vger.kernel.org>,
	LKML <linux-kernel@vger.kernel.org>,
	Bjorn Helgaas <helgaas@kernel.org>,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	Mika Westerberg <mika.westerberg@linux.intel.com>
Subject: Re: [PATCH v2 2/7] PCI: ACPI: PM: Do not use pci_platform_pm_ops for ACPI
Date: Fri, 24 Sep 2021 23:17:11 +0200	[thread overview]
Message-ID: <24c2c653-4087-fba1-5745-a62a8ae715c6@gmail.com> (raw)
In-Reply-To: <CAJZ5v0howP_PudCf-43_HqgW48ydc29SeFVRC-wCm_RNKPBMtA@mail.gmail.com>

Hi

Op 24-09-2021 om 14:02 schreef Rafael J. Wysocki:
> On Thu, Sep 23, 2021 at 10:32 PM Ferry Toth <fntoth@gmail.com> wrote:
>> Hi
>>
>> Op 23-09-2021 om 15:51 schreef Ferry Toth:
>>> Repost (with formatting removed, sorry for the noise)
>>> Op 23-09-2021 om 13:30 schreef Rafael J. Wysocki:
>>>> On Wed, Sep 22, 2021 at 11:31 PM Ferry Toth<fntoth@gmail.com>  wrote:
>>>>> Hi,
>>>>> Op 20-09-2021 om 21:17 schreef Rafael J. Wysocki:
>>>>>> From: Rafael J. Wysocki<rafael.j.wysocki@intel.com>
>>>>>>
>>>>>> Using struct pci_platform_pm_ops for ACPI adds unnecessary
>>>>>> indirection to the interactions between the PCI core and ACPI PM,
>>>>>> which is also subject to retpolines.
>>>>>>
>>>>>> Moreover, it is not particularly clear from the current code that,
>>>>>> as far as PCI PM is concerned, "platform" really means just ACPI
>>>>>> except for the special casess when Intel MID PCI PM is used or when
>>>>>> ACPI support is disabled (through the kernel config or command line,
>>>>>> or because there are no usable ACPI tables on the system).
>>>>>>
>>>>>> To address the above, rework the PCI PM code to invoke ACPI PM
>>>>>> functions directly as needed and drop the acpi_pci_platform_pm
>>>>>> object that is not necessary any more.
>>>>>>
>>>>>> Accordingly, update some of the ACPI PM functions in question to do
>>>>>> extra checks in case the ACPI support is disabled (which previously
>>>>>> was taken care of by avoiding to set the pci_platform_ops pointer
>>>>>> in those cases).
>>>>>>
>>>>>> Signed-off-by: Rafael J. Wysocki<rafael.j.wysocki@intel.com>
>>>>>> ---
>>>>>>
>>>>>> v1 -> v2:
>>>>>>        * Rebase on top of the new [1/7] and move dropping struct
>>>>>>          pci_platform_pm_ops to a separate patch.
>>>>> I wanted to test this series on 5.15-rc2 but this patch 2/7 doesn't
>>>>> apply (after 1/7 applied). Should I apply this on another tree?
>>>> This is on top of
>>>> https://patchwork.kernel.org/project/linux-acpi/patch/2793105.e9J7NaK4W3@kreacher/
>>>>
>>>> which is not yet in any tree.
>>>>
>>>> Sorry for the confusion.
>>> No problem at all. If I can I will try to report back tonight. Else,
>>> will be delayed 2 due to a short break.
>> With those 3 extra patches followed by 7 from this series it builds. But
>> on boot I get:
>> dwc3 dwc3.0.auto: this is not a DesignWare USB3 DRD Core
>> Then after this it reboots. Nothing in the logs. Nothing else on
>> console, I guess something goes wrong early.
> It appears so.
>
> Can you please try just the 3 extra patches this series is on top of?
> The problem is more likely to be located in one of them.
Boots fine with just the 3 so up to and including "ACPI: glue: Look for 
ACPI bus type only if ACPI companion is not known". From the log I get:

Intel MID platform detected, using MID PCI ops
PCI: Using configuration type 1 for base access
..
PCI: Using host bridge windows from ACPI; if necessary, use "pci=nocrs" 
and report a bug
..
PCI: Probing PCI hardware
PCI: root bus 00: using default resources
PCI: Probing PCI hardware (bus 00)
PCI: pci_cache_line_size set to 64 bytes
..
pnp: PnP ACPI init
..
pnp: PnP ACPI: found 2 devices
..
xhci-hcd xhci-hcd.1.auto: xHCI Host Controller
xhci-hcd xhci-hcd.1.auto: new USB bus registered, assigned bus number 1
xhci-hcd xhci-hcd.1.auto: hcc params 0x0220f06c hci version 0x100 quirks 
0x0000000002010010
xhci-hcd xhci-hcd.1.auto: irq 14, io mem 0xf9100000
usb usb1: New USB device found, idVendor=1d6b, idProduct=0002, 
bcdDevice= 5.15
usb usb1: New USB device strings: Mfr=3, Product=2, SerialNumber=1
usb usb1: Product: xHCI Host Controller
usb usb1: Manufacturer: Linux 5.15.0-rc2-edison-acpi-standard xhci-hcd
usb usb1: SerialNumber: xhci-hcd.1.auto
hub 1-0:1.0: USB hub found
hub 1-0:1.0: 1 port detected

I continued up to "PCI: ACPI: PM: Do not use pci_platform_pm_ops for 
ACPI", still boots.

In the logs I still see "Intel MID platform detected, using MID PCI ops".

Unfortunately no more time today, and tomorrow short holiday starts. I 
will continue after returning next Sat.