On 15/03/17 17:49, Andrew Lunn wrote:
> On Wed, Mar 15, 2017 at 05:00:08PM +0200, Roger Quadros wrote:
>> Andrew,
>>
>> On 15/03/17 16:08, Andrew Lunn wrote:
>>> On Wed, Mar 15, 2017 at 03:51:27PM +0200, Roger Quadros wrote:
>>>> Since commit 3c293f4e08b5 ("net: phy: Trigger state machine on state
>>>> change and not polling.")
>>>> phy_suspend() doesn't get called as part of phy_stop() for PHYs using
>>>> interrupts because the phy state machine is never triggered after a
>>>> phy_stop().
>>>>
>>>> Explicitly trigger the PHY state machine so that it can
>>>> see the new PHY state (HALTED) and suspend the PHY.
>>>>
>>>> Signed-off-by: Roger Quadros <rog...@ti.com>
>>>
>>> Hi Roger
>>>
>>> This seems sensible. It mirrors what phy_start() does.
>>>
>>> Reviewed-by: Andrew Lunn <and...@lunn.ch>
>>
>> The reason for this being an RFC was the following comment just before
>> where I add the phy_trigger_machine()
>>
>> /* Cannot call flush_scheduled_work() here as desired because
>> * of rtnl_lock(), but PHY_HALTED shall guarantee phy_change()
>> * will not reenable interrupts.
>> */
>>
>> Is this comment still applicable? If yes, is it OK to call
>> phy_trigger_machine() there?
>
> Humm, good question.
>
> My _guess_ would be, calling it with sync=True could
> deadlock. sync=False is probably safe. But lets see what Florian says.
I agree that we should use phy_trigger_machine() with sync=False.
>
>>
>>>
>>> It does however lead to a follow up question. Are there other places
>>> phydev->state is changed and it is missing a phy_trigger_machine()?
>>>
>>
>> One other place I think we should add phy_trigger_machine() is
>> phy_start_aneg().
>
> Humm, that might get us into a tight loop.
>
> phy_start_aneg() kicks the phy driver to start autoneg and sets
> phydev->state = PHY_AN.
>
> phy_trigger_machine() triggers the state machine immediately.
>
> In state PHY_AN, we check if aneg is done. If not, it sets needs_aneg
> = true. At the end of the state machine, this then calls
> phy_start_aneg(), and it all starts again.
>
> We are missing the 1s delay we have with polling. So for
> phy_start_aneg(), we might need a phy_delayed_trigger_machine(), which
> waits a second before doing anything?
I think that should do the trick.
How about this?
diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
index 8fef03b..162061c 100644
--- a/drivers/net/phy/phy.c
+++ b/drivers/net/phy/phy.c
@@ -630,6 +630,10 @@ int phy_start_aneg(struct phy_device *phydev)
out_unlock:
mutex_unlock(&phydev->lock);
+
+ if (!err)
+ queue_delayed_work(system_power_efficient_wq,
&phydev->state_queue, HZ);
+
return err;
}
EXPORT_SYMBOL(phy_start_aneg);
--
cheers,
-roger
