linux-kernel - Re: [PATCH v12 03/10] drm/display: Add Type-C switch helpers

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: <Y/SvhxgjTM2cYZa+@smile.fi.intel.com>
Date:   Tue, 21 Feb 2023 13:48:23 +0200
From:   Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To:     Pin-yen Lin <treapking@...omium.org>
Cc:     Andrzej Hajda <andrzej.hajda@...el.com>,
        Neil Armstrong <neil.armstrong@...aro.org>,
        Robert Foss <rfoss@...nel.org>,
        Laurent Pinchart <Laurent.pinchart@...asonboard.com>,
        Jonas Karlman <jonas@...boo.se>,
        Jernej Skrabec <jernej.skrabec@...il.com>,
        David Airlie <airlied@...il.com>,
        Daniel Vetter <daniel@...ll.ch>,
        Rob Herring <robh+dt@...nel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
        Daniel Scally <djrscally@...il.com>,
        Heikki Krogerus <heikki.krogerus@...ux.intel.com>,
        Sakari Ailus <sakari.ailus@...ux.intel.com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        "Rafael J . Wysocki" <rafael@...nel.org>,
        Prashant Malani <pmalani@...omium.org>,
        Benson Leung <bleung@...omium.org>,
        Guenter Roeck <groeck@...omium.org>,
        linux-kernel@...r.kernel.org, Hsin-Yi Wang <hsinyi@...omium.org>,
        Marek Vasut <marex@...x.de>,
        Thomas Zimmermann <tzimmermann@...e.de>,
        dri-devel@...ts.freedesktop.org, Xin Ji <xji@...logixsemi.com>,
        Lyude Paul <lyude@...hat.com>,
        Allen Chen <allen.chen@....com.tw>, devicetree@...r.kernel.org,
        AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@...labora.com>,
        Nícolas F . R . A . Prado 
        <nfraprado@...labora.com>, chrome-platform@...ts.linux.dev,
        Javier Martinez Canillas <javierm@...hat.com>,
        linux-acpi@...r.kernel.org, Stephen Boyd <swboyd@...omium.org>,
        Douglas Anderson <dianders@...omium.org>,
        "Gustavo A. R. Silva" <gustavoars@...nel.org>,
        Imre Deak <imre.deak@...el.com>,
        Jani Nikula <jani.nikula@...el.com>,
        Kees Cook <keescook@...omium.org>
Subject: Re: [PATCH v12 03/10] drm/display: Add Type-C switch helpers

On Tue, Feb 21, 2023 at 05:50:47PM +0800, Pin-yen Lin wrote:
> Add helpers to register and unregister Type-C "switches" for bridges
> capable of switching their output between two downstream devices.
> 
> The helper registers USB Type-C mode switches when the "mode-switch"
> and the "reg" properties are available in Device Tree.
> 
> Signed-off-by: Pin-yen Lin <treapking@...omium.org>

...

> +	fwnode_for_each_typec_mode_switch(port, sw)
> +		switch_desc->num_typec_switches++;
> +
> +	if (!switch_desc->num_typec_switches) {
> +		dev_dbg(dev, "No Type-C switches node found\n");
> +		return 0;
> +	}

What about

static inline unsigned int typec_mode_switch_node_count(... *port)
{
	... *sw;
	unsigned int count = 0;

	for_each_typec_mode_switch_node(port, sw)
		count++;

	return count;
}


And then it seems something like

	unsigned int count;

	count = typec_mode_switch_node_count(port);
	if (!count) {
		...
	}

	_switches = count;

...

> +	switch_desc->typec_ports = devm_kcalloc(
> +		dev, switch_desc->num_typec_switches,

Strange indentation.

> +		sizeof(struct drm_dp_typec_port_data), GFP_KERNEL);

> +

Redundant blank line.

> +	if (!switch_desc->typec_ports)
> +		return -ENOMEM;

...

> +void drm_dp_unregister_typec_switches(struct drm_dp_typec_switch_desc *switch_desc)
> +{
> +	int i;

unsigned?

> +	for (i = 0; i < switch_desc->num_typec_switches; i++)
> +		typec_mux_unregister(switch_desc->typec_ports[i].typec_mux);
> +}

...

>  #include <linux/delay.h>
>  #include <linux/i2c.h>
> +#include <linux/usb/typec_mux.h>

I don't see users of this.
But a few forward declarations are missing.

>  #include <drm/display/drm_dp.h>
>  #include <drm/drm_connector.h>

...

> +#define fwnode_for_each_typec_mode_switch(port, sw)	\
> +	fwnode_for_each_child_node((port), (sw))	\
> +		for_each_if(fwnode_property_present((sw), "mode-switch"))

Please don't use fwnode namespace (see above), something like

#define for_each_typec_mode_switch_node(port, sw)	\
	...

-- 
With Best Regards,
Andy Shevchenko