linux-kernel - Re: [PATCH v11 8/9] PCI: Split PME state selection into a local static function

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Date:   Thu, 10 Aug 2023 19:21:55 +0300
From:   Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To:     Mario Limonciello <mario.limonciello@....com>
Cc:     "Rafael J . Wysocki" <rafael@...nel.org>,
        Mika Westerberg <mika.westerberg@...ux.intel.com>,
        Bjorn Helgaas <helgaas@...nel.org>, linux-pci@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-acpi@...r.kernel.org,
        Kuppuswamy Sathyanarayanan 
        <sathyanarayanan.kuppuswamy@...ux.intel.com>,
        Iain Lane <iain@...ngesquash.org.uk>,
        Shyam-sundar S-k <Shyam-sundar.S-k@....com>
Subject: Re: [PATCH v11 8/9] PCI: Split PME state selection into a local
 static function

On Wed, Aug 09, 2023 at 01:54:52PM -0500, Mario Limonciello wrote:
> When a device is not power manageable by the platform, and not already
> in a low power state pci_target_state() will find the deepest state
> that PME is supported and use this to select the wakeup state.
> 
> Simplify this logic and split it out to a local function. No intended
> functional changes.

...

> +static inline pci_power_t pci_get_wake_pme_state(struct pci_dev *dev)
> +{
> +	pci_power_t state = PCI_D3hot;
> +
> +	while (state && !(dev->pme_support & (1 << state)))
> +		state--;
> +
> +	return state;

Sparse won't be happy about this code (with CF=-D__CHECK_ENDIAN__).

Basically it's something like

	return (__force pci_power_t)fls(dev->pme_support & GENMASK(PCI_D3hot, 0));

(but double check and test the logic).

> +}

...

Yeah, I see that is the existing code, perhaps amend it first?

-- 
With Best Regards,
Andy Shevchenko