Re: [PATCH net-next 5/6] net: dsa: mv88e6xxx: add helper for switch ready
From: Andrew Lunn
Date: Wed Nov 30 2016 - 18:38:18 EST
> +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