Re: [PATCH RFC v2 4/4] PCI: hotplug: Add quirk For Dell nvme pcie switches

From: Lukas Wunner <lukas@wunner.de>
To: Alexandru Gagniuc <mr.nuke.me@gmail.com>
Cc: bhelgaas@google.com, austin_bolen@dell.com,
	alex_gagniuc@dellteam.com, keith.busch@intel.com,
	Shyam_Iyer@Dell.com, okaya@kernel.org, linux-pci@vger.kernel.org,
	Mika Westerberg <mika.westerberg@linux.intel.com>,
	Sinan Kaya <okaya@codeaurora.org>,
	Oza Pawandeep <poza@codeaurora.org>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH RFC v2 4/4] PCI: hotplug: Add quirk For Dell nvme pcie switches
Date: Thu, 21 Feb 2019 08:56:34 +0100	[thread overview]
Message-ID: <20190221075634.uih5ysqwkna7cku4@wunner.de> (raw)
In-Reply-To: <20190220012031.10741-5-mr.nuke.me@gmail.com>

On Tue, Feb 19, 2019 at 07:20:30PM -0600, Alexandru Gagniuc wrote:
> --- a/drivers/pci/hotplug/pciehp_hpc.c
> +++ b/drivers/pci/hotplug/pciehp_hpc.c
> @@ -952,3 +952,23 @@ DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_QCOM, 0x0400,
>  			      PCI_CLASS_BRIDGE_PCI, 8, quirk_cmd_compl);
>  DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_QCOM, 0x0401,
>  			      PCI_CLASS_BRIDGE_PCI, 8, quirk_cmd_compl);
> +
> +

Duplicate newline.

> +static void fixup_dell_nvme_backplane_switches(struct pci_dev *pdev)

Can we have a little code comment above the function such as:

+/*
+ * Dell <product name> NVMe storage backplanes disable in-band presence
+ * (PCIe r5.0 sec X.Y.Z) but neglect to set the corresponding flag in the
+ * Slot Capabilities 2 register.
+ */

> +	if (pdev->subsystem_vendor != PCI_VENDOR_ID_DELL
> +		|| pdev->subsystem_device != 0x1fc7)

This looks a little unpolished, how about:

+	if (pdev->subsystem_vendor != PCI_VENDOR_ID_DELL ||
+	    pdev->subsystem_device != 0x1fc7)

> +		return;
> +
> +	pdev->no_in_band_presence = 1;
> +}
> +
> +DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_PLX, 0x9733,

By convention there's no blank line between the closing curly brace
and the DECLARE_PCI_FIXUP_CLASS_FINAL().

If the quirk is x86-specific, please enclose it in "#ifdef CONFIG_X86"
to reduce kernel footprint on other arches.

Thanks,

Lukas