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From: Nathan Chancellor <nathan@kernel.org>
To: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: 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>,
	llvm@lists.linux.dev
Subject: Re: [PATCH v2 2/7] PCI: ACPI: PM: Do not use pci_platform_pm_ops for ACPI
Date: Wed, 29 Sep 2021 12:08:03 -0700	[thread overview]
Message-ID: <YVS5k1H8KyVAk/h8@archlinux-ax161> (raw)
In-Reply-To: <8879480.rMLUfLXkoz@kreacher>

On Mon, Sep 20, 2021 at 09:17:08PM +0200, Rafael J. Wysocki wrote:
> 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>

This patch as commit 9896a58cdd59 ("PCI: ACPI: PM: Do not use
pci_platform_pm_ops for ACPI") in -next causes the following build error
when compiling x86_64 allmodconfig with clang:

drivers/pci/pci-acpi.c:1125:7: error: variable 'adev' is uninitialized when used here [-Werror,-Wuninitialized]
        if (!adev || !acpi_device_power_manageable(adev))
             ^~~~
drivers/pci/pci-acpi.c:1110:26: note: initialize the variable 'adev' to silence this warning
        struct acpi_device *adev;
                                ^
                                 = NULL
1 error generated.

Should the adev assignment be moved up or is there a different fix
necessary?

Cheers,
Nathan

  parent reply	other threads:[~2021-09-29 19:08 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-20 18:52 [PATCH v2 0/7] PCI: ACPI: Get rid of struct pci_platform_pm_ops and clean up code Rafael J. Wysocki
2021-09-20 19:16 ` [PATCH v2 1/7] PCI: PM: Do not use pci_platform_pm_ops for Intel MID PM Rafael J. Wysocki
2021-09-20 19:17 ` [PATCH v2 2/7] PCI: ACPI: PM: Do not use pci_platform_pm_ops for ACPI Rafael J. Wysocki
2021-09-22 21:30   ` Ferry Toth
2021-09-23 11:30     ` Rafael J. Wysocki
     [not found]       ` <013e3a7b-ec67-1a67-c2b9-e1fbb11c664e@gmail.com>
2021-09-23 13:35         ` Rafael J. Wysocki
2021-09-23 13:51       ` Ferry Toth
2021-09-23 20:32         ` Ferry Toth
2021-09-24 12:02           ` Rafael J. Wysocki
2021-09-24 14:52             ` Ferry Toth
2021-09-24 21:17             ` Ferry Toth
2021-09-27 13:46               ` Rafael J. Wysocki
2021-09-29 19:08   ` Nathan Chancellor [this message]
2021-09-29 19:13     ` Rafael J. Wysocki
2021-09-29 19:13       ` Rafael J. Wysocki
2021-09-20 19:17 ` [PATCH v2 3/7] PCI: PM: Drop struct pci_platform_pm_ops Rafael J. Wysocki
2021-09-20 19:17 ` [PATCH v2 4/7] PCI: PM: Rearrange pci_target_state() Rafael J. Wysocki
2021-09-20 19:17 ` [PATCH v2 5/7] PCI: PM: Make pci_choose_state() call pci_target_state() Rafael J. Wysocki
2021-09-20 19:17 ` [PATCH v2 6/7] PCI: PM: Do not call platform_pci_power_manageable() unnecessarily Rafael J. Wysocki
2021-09-20 19:17 ` [PATCH v2 7/7] PCI: PM: Simplify acpi_pci_power_manageable() Rafael J. Wysocki
2021-09-28 23:28 ` [PATCH v2 0/7] PCI: ACPI: Get rid of struct pci_platform_pm_ops and clean up code Bjorn Helgaas
2021-09-29 12:00   ` Rafael J. Wysocki
2021-09-29 15:07     ` Bjorn Helgaas
2021-09-29 17:14   ` Ferry Toth
2021-09-29 18:05 ` [PATCH v3 0/3] PCI: PM: Simplify and unify some helper functions Rafael J. Wysocki
2021-09-29 18:09   ` [PATCH v3 1/3] PCI: PM: Rearrange pci_target_state() Rafael J. Wysocki
2021-09-29 18:11   ` [PATCH v3 2/3] PCI: PM: Make pci_choose_state() call pci_target_state() Rafael J. Wysocki
2021-09-29 18:15   ` [PATCH v3 3/3] PCI: PM: Do not call platform_pci_power_manageable() unnecessarily Rafael J. Wysocki
2021-10-03 20:14   ` [PATCH v3 0/3] PCI: PM: Simplify and unify some helper functions Ferry Toth
2021-10-05 11:03     ` Rafael J. Wysocki

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