RE: [PATCH v5] Add Silicom Platform Driver

[Huibin Shi]

Hi Guenter,

Appreciate your feedback. Please see my comments below.

Thanks
Henry

-----Original Message-----
From: Guenter Roeck <groeck7@xxxxxxxxx> On Behalf Of Guenter Roeck
Sent: Monday, August 28, 2023 8:41 PM
To: Henry Shi <henryshi2018@xxxxxxxxx>
Cc: hbshi69@xxxxxxxxxxx; tglx@xxxxxxxxxxxxx; mingo@xxxxxxxxxx; bp@xxxxxxxxx; dave.hansen@xxxxxxxxxxxxxxx; x86@xxxxxxxxxx; hpa@xxxxxxxxx; hdegoede@xxxxxxxxxx; markgross@xxxxxxxxxx; jdelvare@xxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; platform-driver-x86@xxxxxxxxxxxxxxx; linux-hwmon@xxxxxxxxxxxxxxx; hb_shi2003@xxxxxxxxx; Huibin Shi <henrys@xxxxxxxxxxxxxxx>; Wen Wang <wenw@xxxxxxxxxxxxxxx>
Subject: Re: [PATCH v5] Add Silicom Platform Driver

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On Mon, Aug 28, 2023 at 05:26:22PM -0400, Henry Shi wrote:
> The Silicom platform (silicom-platform) Linux driver for Swisscom 
> Business Box (Swisscom BB) as well as Cordoba family products is a 
> software solution designed to facilitate the efficient management and 
> control of devices through the integration of various Linux 
> frameworks. This platform driver provides seamless support for device 
> management via the Linux LED framework, GPIO framework, Hardware 
> Monitoring (HWMON), and device attributes. The Silicom platform 
> driver's compatibility with these Linux frameworks allows applications 
> to access and control Cordoba family devices using existing software 
> that is compatible with these frameworks. This compatibility 
> simplifies the development process, reduces dependencies on 
> proprietary solutions, and promotes interoperability with other 
> Linux-based systems and software.
>
> Signed-off-by: Henry Shi <henryshi2018@xxxxxxxxx>

Again, my feedback is only for hwmon code.

[ ... ]

> +
> +static int silicom_fan_control_read(struct device *dev,
> +                                                                     enum hwmon_sensor_types type,
> +                                                                     u32 attr, int channel,
> +                                                                     
> +long *val)

Excessively long continuation lines.
That seeme to be the case for almost all continuation lines, except where it is too short. I'd suggest to run the patch through checkpatch --strict and fix what it reports.

total: 0 errors, 9 warnings, 18 checks, 1077 lines checked

is really a bit much.

Henry: OK, I will fix those warnings.

[ ... ]

> +
> +     hwmon_dev = devm_hwmon_device_register_with_info(&device->dev, name, NULL,
> +                             &silicom_chip_info, NULL);

Did you try to compile this with CONFIG_HWMON=n or with CONFIG_HWMON=m and SILICOM_PLATFORM=y ?

Henry: Great question. I did not try that before. When I force "CONFIG_HWMON=m and SILICOM_PLATFORM=y" and compile kernel, the build failed with message "silicom-platform.c:(.init.text+0x8ff5b): undefined reference to `devm_hwmon_device_register_with_info'". I tried following change in drivers/platform/x86/Kconfig:

config SILICOM_PLATFORM
	tristate "Silicom Edge Networking device support"
	depends on DMI
	select LEDS_CLASS_MULTICOLOR
	select GPIOLIB
	select HWMON  ----> added 
	help
	  This option enables support for the LEDs/GPIO/etc downstream of the
	  embedded controller on Silicom "Cordoba" hardware and derivatives.

	  If you have a Silicom network appliance, say Y or M here.

After this change, kernel build can be completed. And "CONFIG_HWMON" was changed to "y" in .config file. Not sure whether there are any other better ways to resolve CONFIG dependence in when adding a new kernel driver. 




Guenter