Re: [PATCH] drivers: block: skd: remove skd_pci_info()

From: Chaitanya Kulkarni <Chaitanya.Kulkarni@wdc.com>
To: Puranjay Mohan <puranjay12@gmail.com>,
	"bjorn@helgaas.com" <bjorn@helgaas.com>,
	"linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>,
	Damien Le Moal <Damien.LeMoal@wdc.com>,
	"axboe@kernel.dk" <axboe@kernel.dk>,
	"linux-block@vger.kernel.org" <linux-block@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] drivers: block: skd: remove skd_pci_info()
Date: Fri, 11 Dec 2020 21:50:52 +0000	[thread overview]
Message-ID: <BYAPR04MB496513CB49E42A3467427BF686CA0@BYAPR04MB4965.namprd04.prod.outlook.com> (raw)
In-Reply-To: 20201211164137.8605-1-puranjay12@gmail.com

On 12/11/20 08:45, Puranjay Mohan wrote:
> PCI core calls __pcie_print_link_status() for every device, it prints
> both the link width and the link speed. skd_pci_info() does the same
> thing again, hence it can be removed.
>
> Signed-off-by: Puranjay Mohan <puranjay12@gmail.com>
> ---
>  drivers/block/skd_main.c | 31 -------------------------------
>  1 file changed, 31 deletions(-)
>
> diff --git a/drivers/block/skd_main.c b/drivers/block/skd_main.c
> index a962b4551bed..da7aac5335d9 100644
> --- a/drivers/block/skd_main.c
> +++ b/drivers/block/skd_main.c
> @@ -3134,40 +3134,11 @@ static const struct pci_device_id skd_pci_tbl[] = {
>  
>  MODULE_DEVICE_TABLE(pci, skd_pci_tbl);
>  
> -static char *skd_pci_info(struct skd_device *skdev, char *str)
> -{
> -	int pcie_reg;
> -
> -	strcpy(str, "PCIe (");
> -	pcie_reg = pci_find_capability(skdev->pdev, PCI_CAP_ID_EXP);
> -
> -	if (pcie_reg) {
> -
> -		char lwstr[6];
> -		uint16_t pcie_lstat, lspeed, lwidth;
> -
> -		pcie_reg += 0x12;
> -		pci_read_config_word(skdev->pdev, pcie_reg, &pcie_lstat);
> -		lspeed = pcie_lstat & (0xF);
> -		lwidth = (pcie_lstat & 0x3F0) >> 4;
> -
> -		if (lspeed == 1)
> -			strcat(str, "2.5GT/s ");
> -		else if (lspeed == 2)
> -			strcat(str, "5.0GT/s ");
> -		else
> -			strcat(str, "<unknown> ");
The skd driver prints unknown if the speed is not "2.5GT/s" or "5.0GT/s".
__pcie_print_link_status()  prints "unknown" only if speed
value >= ARRAY_SIZE(speed_strings).

If a buggy skd card returns value that is not != ("2.5GT/s" or "5.0GT/s")
&& value < ARRAY_SIZE(speed_strings) then it will not print the unknown but
the value from speed string array.

Which breaks the current behavior. Please correct me if I'm wrong.
> -		snprintf(lwstr, sizeof(lwstr), "%dX)", lwidth);
> -		strcat(str, lwstr);
> -	}
> -	return str;
> -}
>  
>  static int skd_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
>  {
>  	int i;
>  	int rc = 0;
> -	char pci_str[32];
>  	struct skd_device *skdev;
>  
>  	dev_dbg(&pdev->dev, "vendor=%04X device=%04x\n", pdev->vendor,
> @@ -3201,8 +3172,6 @@ static int skd_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
>  		goto err_out_regions;
>  	}
>  
> -	skd_pci_info(skdev, pci_str);
> -	dev_info(&pdev->dev, "%s 64bit\n", pci_str);
>  
>  	pci_set_master(pdev);
>  	rc = pci_enable_pcie_error_reporting(pdev);