linux-kernel - Re: [PATCH 03/28] thunderbolt: Enable TMU access when accessing port space on legacy devices

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Message-ID: <20190129215858.c2yws2ce76d7qm62@wunner.de>
Date:   Tue, 29 Jan 2019 22:58:58 +0100
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>
Subject: Re: [PATCH 03/28] thunderbolt: Enable TMU access when accessing port
 space on legacy devices

On Tue, Jan 29, 2019 at 06:01:18PM +0300, Mika Westerberg wrote:
> +	if (enable)
> +		value |= BIT(20);

Can we have a macro for this bit?


> +int tb_port_find_cap(struct tb_port *port, enum tb_port_cap cap)
> +{
> +	int ret;
> +
> +	ret = tb_port_enable_tmu(port, true);
> +	if (ret)
> +		return ret;
> +
> +	ret = __tb_port_find_cap(port, cap);
> +
> +	tb_port_enable_tmu(port, false);
> +
> +	return ret;
> +}

Would there be a downside to setting the TMU bit on all ports all the time
(e.g. on switch enumeration)?

Thanks,

Lukas