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

From: Vivien Didelot
Date: Thu Dec 01 2016 - 15:31:16 EST


Hi Andrew,

Andrew Lunn <andrew@xxxxxxx> writes:

> 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()

That won't work. the _wait() helpers are made to wait on self-clear (SC)
bits, i.e. looping until they are cleared to zero.

Here we want the opposite.

I will keep this existing wait loop for the moment and work soon on a
new patchset to rework the wait routines. We need a generic access to
test a given value against a given mask and wrappers for busy bits, etc.

>> +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.

That is better indeed.

Thanks,

Vivien