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Date:   Tue, 16 Feb 2021 18:53:03 +0100
From:   Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= <kw@linux.com>
To:     Dejin Zheng <zhengdejin5@gmail.com>
Cc:     corbet@lwn.net, jarkko.nikula@linux.intel.com,
        andriy.shevchenko@linux.intel.com, mika.westerberg@linux.intel.com,
        rric@kernel.org, helgaas@kernel.org, wsa@kernel.org,
        linux-doc@vger.kernel.org, linux-i2c@vger.kernel.org,
        linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 1/4] PCI: Introduce pcim_alloc_irq_vectors()
Message-ID: <YCwGf6vSsNoVxgPp@rocinante>
References: <20210216160249.749799-1-zhengdejin5@gmail.com>
 <20210216160249.749799-2-zhengdejin5@gmail.com>
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In-Reply-To: <20210216160249.749799-2-zhengdejin5@gmail.com>
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Hi Dejin,

> Introduce pcim_alloc_irq_vectors(), a device-managed version of
> pci_alloc_irq_vectors(). Introducing this function can simplify
> the error handling path in many drivers.
> 
> And use pci_free_irq_vectors() to replace some code in pcim_release(),
> they are equivalent, and no functional change. It is more explicit
> that pcim_alloc_irq_vectors() is a device-managed function.
[...]

Some suggestions about the commit message as per:

  https://lore.kernel.org/linux-pci/YCwE2cf9X%2FGd6lWy@rocinante/

> +/**
> + * pcim_alloc_irq_vectors - a device-managed pci_alloc_irq_vectors()
> + * @dev:		PCI device to operate on
> + * @min_vecs:		minimum number of vectors required (must be >= 1)
> + * @max_vecs:		maximum (desired) number of vectors
> + * @flags:		flags or quirks for the allocation
> + *
> + * Return the number of vectors allocated, (which might be smaller than
> + * @max_vecs) if successful, or a negative error code on error. If less
> + * than @min_vecs interrupt vectors are available for @dev the function
> + * will fail with -ENOSPC.
> + *
> + * It depends on calling pcim_enable_device() to make IRQ resources
> + * manageable.
> + */
> +int pcim_alloc_irq_vectors(struct pci_dev *dev, unsigned int min_vecs,
> +				unsigned int max_vecs, unsigned int flags)
> +{
> +	struct pci_devres *dr;
> +
> +	dr = find_pci_dr(dev);
> +	if (!dr || !dr->enabled)
> +		return -EINVAL;
> +
> +	return pci_alloc_irq_vectors(dev, min_vecs, max_vecs, flags);
> +}
> +EXPORT_SYMBOL(pcim_alloc_irq_vectors);
[...]

Looks good!  Thank you for adding kernel-doc here!  Much appreciated.

Reviewed-by: Krzysztof Wilczyński <kw@linux.com>

Krzysztof