linux-kernel - Re: [PATCH v3 8/8] memory: gpmc-omap: "gpmc,device-width" DT property is optional

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <aa465bd9-b3d5-8d75-3e59-e86c2cd093cd@canonical.com>
Date:   Tue, 7 Sep 2021 14:36:46 +0200
From:   Krzysztof Kozlowski <krzysztof.kozlowski@...onical.com>
To:     Roger Quadros <rogerq@...nel.org>, tony@...mide.com
Cc:     robh+dt@...nel.org, grygorii.strashko@...com, nm@...com,
        lokeshvutla@...com, nsekhar@...com, miquel.raynal@...tlin.com,
        devicetree@...r.kernel.org, linux-mtd@...ts.infradead.org,
        linux-omap@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3 8/8] memory: gpmc-omap: "gpmc,device-width" DT property
 is optional

On 07/09/2021 13:32, Roger Quadros wrote:
> Check for valid gpmc,device-width, nand-bus-width and bank-width
> at one place. Default to 8-bit width if none present.

I don't understand the message in the context of the patch. The title
says one property is optional - that's it. The message says you
consolidate checks. How is this related to the title?

The patch itself moves around checking of properties and reads
nand-bus-width *always*. It does not "check at one place" but rather
"check always". In the same time, the patch does not remove
gpmc,device-width check in other place.

All three elements - the title, message and patch - do different things.
What did you want to achieve here? Can you help in clarifying it?


Best regards,
Krzysztof


> 
> Signed-off-by: Roger Quadros <rogerq@...nel.org>
> ---
>  drivers/memory/omap-gpmc.c | 41 ++++++++++++++++++++++++--------------
>  1 file changed, 26 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/memory/omap-gpmc.c b/drivers/memory/omap-gpmc.c
> index f80c2ea39ca4..32d7c665f33c 100644
> --- a/drivers/memory/omap-gpmc.c
> +++ b/drivers/memory/omap-gpmc.c
> @@ -2171,10 +2171,8 @@ static int gpmc_probe_generic_child(struct platform_device *pdev,
>  		}
>  	}
>  
> -	if (of_device_is_compatible(child, "ti,omap2-nand")) {
> -		/* NAND specific setup */
> -		val = 8;
> -		of_property_read_u32(child, "nand-bus-width", &val);
> +	/* DT node can have "nand-bus-width" or "bank-width" or "gpmc,device-width" */
> +	if (!of_property_read_u32(child, "nand-bus-width", &val)) {
>  		switch (val) {
>  		case 8:
>  			gpmc_s.device_width = GPMC_DEVWIDTH_8BIT;
> @@ -2183,24 +2181,37 @@ static int gpmc_probe_generic_child(struct platform_device *pdev,
>  			gpmc_s.device_width = GPMC_DEVWIDTH_16BIT;
>  			break;
>  		default:
> -			dev_err(&pdev->dev, "%pOFn: invalid 'nand-bus-width'\n",
> -				child);
> +			dev_err(&pdev->dev,
> +				"%pOFn: invalid 'nand-bus-width':%d\n", child, val);
> +			ret = -EINVAL;
> +			goto err;
> +		}
> +	} else if (!of_property_read_u32(child, "bank-width", &val)) {
> +		if (val != 1 && val != 2) {
> +			dev_err(&pdev->dev,
> +				"%pOFn: invalid 'bank-width':%d\n", child, val);
>  			ret = -EINVAL;
>  			goto err;
>  		}
> +		gpmc_s.device_width = val;
> +	} else if (!of_property_read_u32(child, "gpmc,device-width", &val)) {
> +		if (val != 1 && val != 2) {
> +			dev_err(&pdev->dev,
> +				"%pOFn: invalid 'gpmc,device-width':%d\n", child, val);
> +			ret = -EINVAL;
> +			goto err;
> +		}
> +		gpmc_s.device_width = val;
> +	} else {
> +		/* default to 8-bit */
> +		gpmc_s.device_width = GPMC_DEVWIDTH_8BIT;
> +	}
>  
> +	if (of_device_is_compatible(child, "ti,omap2-nand")) {
> +		/* NAND specific setup */
>  		/* disable write protect */
>  		gpmc_configure(GPMC_CONFIG_WP, 0);
>  		gpmc_s.device_nand = true;
> -	} else {
> -		ret = of_property_read_u32(child, "bank-width",
> -					   &gpmc_s.device_width);
> -		if (ret < 0 && !gpmc_s.device_width) {
> -			dev_err(&pdev->dev,
> -				"%pOF has no 'gpmc,device-width' property\n",
> -				child);
> -			goto err;
> -		}
>  	}
>  
>  	/* Reserve wait pin if it is required and valid */
>