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From:   Damien Le Moal <Damien.LeMoal@wdc.com>
To:     Frederick Lawler <fred@fredlawl.com>,
        "axboe@kernel.dk" <axboe@kernel.dk>
CC:     "linux-block@vger.kernel.org" <linux-block@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "bhelgaas@google.com" <bhelgaas@google.com>,
        "bvanassche@acm.org" <bvanassche@acm.org>
Subject: Re: [PATCH v2 1/4] skd: Prefer pcie_capability_read_word()
Thread-Topic: [PATCH v2 1/4] skd: Prefer pcie_capability_read_word()
Thread-Index: AQHVnaYWjyRplcnjK0O+FGDAzAO+yA==
Date:   Mon, 18 Nov 2019 01:45:33 +0000
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References: <20191118002057.9596-1-fred@fredlawl.com>
 <20191118002057.9596-2-fred@fredlawl.com>
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On 2019/11/18 9:21, Frederick Lawler wrote:=0A=
> Commit 8c0d3a02c130 ("PCI: Add accessors for PCI Express Capability")=0A=
> added accessors for the PCI Express Capability so that drivers didn't=0A=
> need to be aware of differences between v1 and v2 of the PCI=0A=
> Express Capability.=0A=
> =0A=
> Replace pci_read_config_word() and pci_write_config_word() calls with=0A=
> pcie_capability_read_word() and pcie_capability_write_word().=0A=
> =0A=
> Signed-off-by: Frederick Lawler <fred@fredlawl.com>=0A=
> ---=0A=
>  drivers/block/skd_main.c | 8 ++------=0A=
>  1 file changed, 2 insertions(+), 6 deletions(-)=0A=
> =0A=
> diff --git a/drivers/block/skd_main.c b/drivers/block/skd_main.c=0A=
> index 51569c199a6c..f25f6ef6b4c7 100644=0A=
> --- a/drivers/block/skd_main.c=0A=
> +++ b/drivers/block/skd_main.c=0A=
> @@ -3134,18 +3134,14 @@ MODULE_DEVICE_TABLE(pci, skd_pci_tbl);=0A=
>  =0A=
>  static char *skd_pci_info(struct skd_device *skdev, char *str)=0A=
>  {=0A=
> -	int pcie_reg;=0A=
> -=0A=
>  	strcpy(str, "PCIe (");=0A=
> -	pcie_reg =3D pci_find_capability(skdev->pdev, PCI_CAP_ID_EXP);=0A=
>  =0A=
> -	if (pcie_reg) {=0A=
> +	if (pci_is_pcie(skdev->pdev)) {=0A=
=0A=
Maybe return early here ? The reason is that if pci_is_pcie() is false,=0A=
then the string "PCIe (" is not terminated with a closing parenthesis.=0A=
So something like:=0A=
=0A=
	if (!pci_is_pcie(skdev->pdev)) {=0A=
		strcat(str, ")");=0A=
		return str;=0A=
	}=0A=
=0A=
May be better. Note that the "return str" is also rather pointless since=0A=
it is not used by the caller of skd_pci_info().=0A=
=0A=
>  =0A=
>  		char lwstr[6];=0A=
>  		uint16_t pcie_lstat, lspeed, lwidth;=0A=
>  =0A=
> -		pcie_reg +=3D 0x12;=0A=
> -		pci_read_config_word(skdev->pdev, pcie_reg, &pcie_lstat);=0A=
> +		pcie_capability_read_word(skdev->pdev, 0x12, &pcie_lstat);=0A=
>  		lspeed =3D pcie_lstat & (0xF);=0A=
>  		lwidth =3D (pcie_lstat & 0x3F0) >> 4;=0A=
>  =0A=
> =0A=
=0A=
=0A=
-- =0A=
Damien Le Moal=0A=
Western Digital Research=0A=