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From: Andrew Lunn <andrew@lunn•ch>
To: Vivien Didelot <vivien.didelot@savoirfairelinux•com>
Cc: netdev@vger•kernel.org, linux-kernel@vger•kernel.org,
	kernel@savoirfairelinux•com,
	"David S. Miller" <davem@davemloft•net>,
	Florian Fainelli <f.fainelli@gmail•com>
Subject: Re: [PATCH net-next 5/6] net: dsa: mv88e6xxx: add helper for switch ready
Date: Thu, 1 Dec 2016 00:38:10 +0100	[thread overview]
Message-ID: <20161130233810.GT21645@lunn.ch> (raw)
In-Reply-To: <20161130225930.25510-6-vivien.didelot@savoirfairelinux.com>

> +static int mv88e6xxx_wait_switch_ready(struct mv88e6xxx_chip *chip)
> +{
> +	const unsigned long timeout = jiffies + 1 * HZ;
> +	bool ready;
> +	int err;
> +
> +	/* Wait up to 1 second for switch to be ready.
> +	 * The switch is ready when all units inside the device (ATU, VTU, etc.)
> +	 * have finished their initialization and are ready to accept frames.
> +	 */
> +	while (time_before(jiffies, timeout)) {
> +		err = mv88e6xxx_g1_init_ready(chip, &ready);
> +		if (err)
> +			return err;
> +
> +		if (ready)
> +			break;
> +
> +		usleep_range(1000, 2000);
> +	}
> +
> +	if (time_after(jiffies, timeout))
> +		return -ETIMEDOUT;

As we have seen in the past, this sort of loop is broken if we end up
sleeping for a long time. Please take the opportunity to replace it
with one of our _wait() helpers, e.g. mv88e6xxx_g1_wait()

> +int mv88e6xxx_g1_init_ready(struct mv88e6xxx_chip *chip, bool *ready)
> +{
> +	u16 val;
> +	int err;
> +
> +	/* Check the value of the InitReady bit 11 */
> +	err = mv88e6xxx_g1_read(chip, GLOBAL_STATUS, &val);
> +	if (err)
> +		return err;
> +
> +	*ready = !!(val & GLOBAL_STATUS_INIT_READY);

I would actually do the wait here.

> +
> +	return 0;
> +}
> +

Thanks

  Andrew

next prev parent reply	other threads:[~2016-11-30 23:38 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-11-30 22:59 [PATCH net-next 0/6] net: dsa: mv88e6xxx: rework reset and PPU code Vivien Didelot
2016-11-30 22:59 ` [PATCH net-next 1/6] net: dsa: mv88e6xxx: add helper to disable ports Vivien Didelot
2016-11-30 23:20   ` Andrew Lunn
2016-11-30 22:59 ` [PATCH net-next 2/6] net: dsa: mv88e6xxx: add helper to hardware reset Vivien Didelot
2016-11-30 23:21   ` Andrew Lunn
2016-11-30 22:59 ` [PATCH net-next 3/6] net: dsa: mv88e6xxx: add a software reset op Vivien Didelot
2016-11-30 23:26   ` Andrew Lunn
2016-12-01 20:41     ` Vivien Didelot
2016-12-02 15:43       ` Andrew Lunn
2016-12-02 17:30         ` Vivien Didelot
2016-12-02 17:23   ` David Miller
2016-11-30 22:59 ` [PATCH net-next 4/6] net: dsa: mv88e6xxx: add a PPU polling op Vivien Didelot
2016-11-30 22:59 ` [PATCH net-next 5/6] net: dsa: mv88e6xxx: add helper for switch ready Vivien Didelot
2016-11-30 23:38   ` Andrew Lunn [this message]
2016-12-01 20:31     ` Vivien Didelot
2016-11-30 22:59 ` [PATCH net-next 6/6] net: dsa: mv88e6xxx: add PPU enable/disable ops Vivien Didelot

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