linux-kernel - Re: [PATCH v3 12/36] thunderbolt: Properly disable path

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Date:   Sun, 31 Mar 2019 17:24:58 +0200
From:   Lukas Wunner <lukas@...ner.de>
To:     Mika Westerberg <mika.westerberg@...ux.intel.com>
Cc:     linux-kernel@...r.kernel.org,
        Michael Jamet <michael.jamet@...el.com>,
        Yehezkel Bernat <YehezkelShB@...il.com>,
        Andreas Noever <andreas.noever@...il.com>,
        Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        Christian Kellner <ckellner@...hat.com>,
        Mario.Limonciello@...l.com
Subject: Re: [PATCH v3 12/36] thunderbolt: Properly disable path

On Thu, Mar 28, 2019 at 03:36:09PM +0300, Mika Westerberg wrote:
> +static int __tb_path_deactivate_hop(struct tb_port *port, int hop_index)
> +{
> +	struct tb_regs_hop hop;
> +	ktime_t timeout;
> +	int ret;
> +
> +	if (port->sw->is_unplugged)
> +		return 0;

This check is basically a duplication of the checks added in patch 4 ...


> +
> +	/* Disable the path */
> +	ret = tb_port_read(port, &hop, TB_CFG_HOPS, 2 * hop_index, 2);
> +	if (ret)
> +		return ret;
[...]
>  static void __tb_path_deactivate_hops(struct tb_path *path, int first_hop)
>  {
>  	int i, res;
> -	struct tb_regs_hop hop = { };
> +
>  	for (i = first_hop; i < path->path_length; i++) {
> -		res = tb_port_write(path->hops[i].in_port, &hop, TB_CFG_HOPS,
> -				    2 * path->hops[i].in_hop_index, 2);
> +		res = __tb_path_deactivate_hop(path->hops[i].in_port,
> +					       path->hops[i].in_hop_index);
>  		if (res)
>  			tb_port_warn(path->hops[i].in_port,
>  				     "hop deactivation failed for hop %d, index %d\n",

... however you return 0 above to avoid the warning here whereas the checks
added in patch 4 return -ENODEV.  You may want to change "if (res)" to
"if (res && res != -ENODEV)" and drop the unplugged check in
__tb_path_deactivate_hop().

Thanks,

Lukas