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Re: [PATCH net-next 5/6] net: dsa: mv88e6xxx: add helper for switch ready

From Andrew Lunn <andrew@lunn.ch>
Newsgroups linux.kernel
Subject Re: [PATCH net-next 5/6] net: dsa: mv88e6xxx: add helper for switch ready
Date 2016-12-01 00:40 +0100
Message-ID <sJmDM-4jD-13@gated-at.bofh.it> (permalink)
References <sJmaJ-472-7@gated-at.bofh.it> <sJmaJ-472-25@gated-at.bofh.it>
Organization linux.* mail to news gateway

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> +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

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Thread

[PATCH net-next 0/6] net: dsa: mv88e6xxx: rework reset and PPU code Vivien Didelot <vivien.didelot@savoirfairelinux.com> - 2016-12-01 00:10 +0100
  [PATCH net-next 6/6] net: dsa: mv88e6xxx: add PPU enable/disable ops Vivien Didelot <vivien.didelot@savoirfairelinux.com> - 2016-12-01 00:10 +0100
  [PATCH net-next 2/6] net: dsa: mv88e6xxx: add helper to hardware reset Vivien Didelot <vivien.didelot@savoirfairelinux.com> - 2016-12-01 00:10 +0100
    Re: [PATCH net-next 2/6] net: dsa: mv88e6xxx: add helper to hardware  reset Andrew Lunn <andrew@lunn.ch> - 2016-12-01 00:30 +0100
  [PATCH net-next 1/6] net: dsa: mv88e6xxx: add helper to disable ports Vivien Didelot <vivien.didelot@savoirfairelinux.com> - 2016-12-01 00:10 +0100
    Re: [PATCH net-next 1/6] net: dsa: mv88e6xxx: add helper to disable  ports Andrew Lunn <andrew@lunn.ch> - 2016-12-01 00:30 +0100
  [PATCH net-next 3/6] net: dsa: mv88e6xxx: add a software reset op Vivien Didelot <vivien.didelot@savoirfairelinux.com> - 2016-12-01 00:10 +0100
    Re: [PATCH net-next 3/6] net: dsa: mv88e6xxx: add a software reset op Andrew Lunn <andrew@lunn.ch> - 2016-12-01 00:30 +0100
      Re: [PATCH net-next 3/6] net: dsa: mv88e6xxx: add a software reset op Vivien Didelot <vivien.didelot@savoirfairelinux.com> - 2016-12-01 21:50 +0100
        Re: [PATCH net-next 3/6] net: dsa: mv88e6xxx: add a software reset op Andrew Lunn <andrew@lunn.ch> - 2016-12-02 16:50 +0100
          Re: [PATCH net-next 3/6] net: dsa: mv88e6xxx: add a software reset op Vivien Didelot <vivien.didelot@savoirfairelinux.com> - 2016-12-02 18:40 +0100
    Re: [PATCH net-next 3/6] net: dsa: mv88e6xxx: add a software reset  op David Miller <davem@davemloft.net> - 2016-12-02 18:30 +0100
  [PATCH net-next 5/6] net: dsa: mv88e6xxx: add helper for switch ready Vivien Didelot <vivien.didelot@savoirfairelinux.com> - 2016-12-01 00:10 +0100
    Re: [PATCH net-next 5/6] net: dsa: mv88e6xxx: add helper for switch  ready Andrew Lunn <andrew@lunn.ch> - 2016-12-01 00:40 +0100
      Re: [PATCH net-next 5/6] net: dsa: mv88e6xxx: add helper for switch ready Vivien Didelot <vivien.didelot@savoirfairelinux.com> - 2016-12-01 21:40 +0100
  [PATCH net-next 4/6] net: dsa: mv88e6xxx: add a PPU polling op Vivien Didelot <vivien.didelot@savoirfairelinux.com> - 2016-12-01 00:10 +0100

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