public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Heikki Krogerus <heikki.krogerus@linux.intel.com>
To: Sebastian Reichel <sebastian.reichel@collabora.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	linux-rockchip@lists.infradead.org, linux-usb@vger.kernel.org,
	linux-kernel@vger.kernel.org, kernel@collabora.com
Subject: Re: [PATCH 1/2] usb: typec: mux: avoid duplicated orientation switches
Date: Mon, 23 Feb 2026 16:54:44 +0200	[thread overview]
Message-ID: <aZxqNJCsUMaBlMmB@kuha> (raw)
In-Reply-To: <20260213-typec-mux-duplication-fix-v1-1-70076a7c5691@collabora.com>

Hi Sebastian,

Fri, Feb 13, 2026 at 08:23:28PM +0100, Sebastian Reichel wrote:
> Some devices use combo PHYs (i.e. USB3 + DisplayPort), which also
> handle the orientation mux. These PHYs are referenced twice from
> the USB-C connector (USB super-speed lines and SBU/AUX lines)
> resulting in the switch being configured twice. Avoid this by
> dropping duplicates.
> 
> Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
> ---
>  drivers/usb/typec/mux.c | 14 +++++++++++++-
>  1 file changed, 13 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/typec/mux.c b/drivers/usb/typec/mux.c
> index 182c902c42f6..db35b7398343 100644
> --- a/drivers/usb/typec/mux.c
> +++ b/drivers/usb/typec/mux.c
> @@ -72,9 +72,9 @@ struct typec_switch *fwnode_typec_switch_get(struct fwnode_handle *fwnode)
>  {
>  	struct typec_switch_dev *sw_devs[TYPEC_MUX_MAX_DEVS];
>  	struct typec_switch *sw;
> +	int i, j, k;
>  	int count;
>  	int err;
> -	int i;
>  
>  	sw = kzalloc(sizeof(*sw), GFP_KERNEL);
>  	if (!sw)
> @@ -96,6 +96,18 @@ struct typec_switch *fwnode_typec_switch_get(struct fwnode_handle *fwnode)
>  		}
>  	}
>  
> +	/* eliminate duplicates */
> +	for (i = 0; i < count; i++) {
> +		for (j = i + 1; j < count; j++) {
> +			if (sw_devs[j] == sw_devs[i]) {
> +				put_device(&sw_devs[j]->dev);
> +				for (k = j; k < count; k++)
> +					sw_devs[k] = sw_devs[k+1];
> +				count--;
> +			}
> +		}
> +	}

I think that check could be done in typec_switch_match(). Just pass
that sw_devs to it as "data":

        -        count = fwnode_connection_find_matches(fwnode, "orientation-switch", NULL,
        +        count = fwnode_connection_find_matches(fwnode, "orientation-switch", sw_devs,

And then in typec_switch_match(), probable as the second last step:

         static void *typec_switch_match(const struct fwnode_handle *fwnode,
                                         const char *id, void *data)
         {
        +       struct typec_switch_dev *sw_devs = data;
        +       int i;
                ...
                dev = class_find_device(&typec_mux_class, NULL, fwnode,
                                        switch_fwnode_match);

        +	/* Skip duplicates */
        +       for (i = 0; i < TYPEC_MUX_MAX_DEVS; i++)
        +               if (to_typec_switch_dev(dev) == sw_devs[i]) {
        +                       put_device(dev);
        +                       return NULL;
        +               }

                return dev ? to_typec_switch_dev(dev) : ERR_PTR(-EPROBE_DEFER);
         }

thanks,

-- 
heikki

  reply	other threads:[~2026-02-23 14:55 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-02-13 19:23 [PATCH 0/2] usb: typec: mux: avoid duplicated mux switches Sebastian Reichel
2026-02-13 19:23 ` [PATCH 1/2] usb: typec: mux: avoid duplicated orientation switches Sebastian Reichel
2026-02-23 14:54   ` Heikki Krogerus [this message]
2026-02-13 19:23 ` [PATCH 2/2] usb: typec: mux: avoid duplicated mux switches Sebastian Reichel
2026-02-23 15:02   ` Heikki Krogerus

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=aZxqNJCsUMaBlMmB@kuha \
    --to=heikki.krogerus@linux.intel.com \
    --cc=gregkh@linuxfoundation.org \
    --cc=kernel@collabora.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-rockchip@lists.infradead.org \
    --cc=linux-usb@vger.kernel.org \
    --cc=sebastian.reichel@collabora.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox