linux-kernel - Re: [PATCH v4 4/7] platform/chrome: cros_ec

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Message-ID: <CAE-0n52AG8henLkzAyO112pBmNAskcC0SXKFNCyQQ3MG01xkGg@mail.gmail.com>
Date: Tue, 10 Dec 2024 15:32:20 -0800
From: Stephen Boyd <swboyd@...omium.org>
To: Abhishek Pandit-Subedi <abhishekpandit@...omium.org>, chrome-platform@...ts.linux.dev, 
	heikki.krogerus@...ux.intel.com, linux-usb@...r.kernel.org, 
	tzungbi@...nel.org
Cc: akuchynski@...gle.com, pmalani@...omium.org, jthies@...gle.com, 
	dmitry.baryshkov@...aro.org, badhri@...gle.com, rdbabiera@...gle.com, 
	Benson Leung <bleung@...omium.org>, Guenter Roeck <groeck@...omium.org>, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v4 4/7] platform/chrome: cros_ec_typec: Update partner
 altmode active

Quoting Abhishek Pandit-Subedi (2024-12-06 15:38:15)
> diff --git a/drivers/platform/chrome/cros_ec_typec.c b/drivers/platform/chrome/cros_ec_typec.c
> index c7781aea0b88..e3eabe5e42ac 100644
> --- a/drivers/platform/chrome/cros_ec_typec.c
> +++ b/drivers/platform/chrome/cros_ec_typec.c
> @@ -676,6 +677,16 @@ static int cros_typec_configure_mux(struct cros_typec_data *typec, int port_num,
>                         port->mux_flags);
>         }
>
> +       /* Iterate all partner alt-modes and set the active alternate mode. */
> +       list_for_each_entry_safe(node, n, &port->partner_mode_list, list) {

This can just be list_for_each_entry() because the list isn't changing
during iteration.

> +               if (port->state.alt != NULL &&
> +                   node->amode->svid == port->state.alt->svid) {
> +                       typec_altmode_update_active(node->amode, true);
> +               } else {
> +                       typec_altmode_update_active(node->amode, false);
> +               }

It could also be shorter:

	list_for_each_entry(node, &port->partner_mode_list, list) {
		typec_altmode_update_active(node->amode,
			port->state.alt && node->amode->svid == port->state.alt->svid);
	}

As far as I can tell, cros_typec_configure_mux() is called when the HPD
state changes. We'll iterate through here unnecessarily in that case.
Can that be avoided somehow?

> +
>  mux_ack:
>         if (!typec->needs_mux_ack)
>                 return ret;