netdev - Re: Problem with PHY state machine when using interrupts

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Date:   Mon, 24 Jul 2017 15:39:07 -0700
From:   Florian Fainelli <f.fainelli@...il.com>
To:     Mason <slash.tmp@...e.fr>, Andrew Lunn <andrew@...n.ch>,
        Mans Rullgard <mans@...sr.com>
Cc:     netdev <netdev@...r.kernel.org>,
        Linux ARM <linux-arm-kernel@...ts.infradead.org>
Subject: Re: Problem with PHY state machine when using interrupts

On 07/24/2017 03:36 PM, Florian Fainelli wrote:
> On 07/24/2017 02:20 PM, Mason wrote:
>> On 24/07/2017 21:53, Florian Fainelli wrote:
>>
>>> Well now that I see the possible interrupts generated, I indeed don't
>>> see how you can get a link down notification unless you somehow force
>>> the link down yourself, which would certainly happen in phy_suspend()
>>> when we set BMCR.pwrdwn, but that may be too late.
>>>
>>> You should still expect the adjust_link() function to be called though
>>> with PHY_HALTED being set and that takes care of doing phydev->link = 0
>>> and netif_carrier_off(). If that still does not work, then see whether
>>> removing the call to phy_stop() does help (it really should).
>>
>> The only functions setting phydev->state to PHY_HALTED
>> are phy_error() and phy_stop() AFAICT.
>>
>> I am aware that when phy_state_machine() handles the
>> PHY_HALTED state, it will set phydev->link = 0;
>> and call netif_carrier_off() -- because that's where
>> I copied that code from.
>>
>> My issue is that phy_state_machine() does not run when
>> I run 'ip set link dev eth0 down' from the command line.
> 
> Yes, that much is clear, which is why I suggested earlier you try the
> patch at the end now.

This sentence was referring to this patch that I changed mid way through
this email:

diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
index d0626bf5c540..652e24b53f3f 100644
--- a/drivers/net/phy/phy.c
+++ b/drivers/net/phy/phy.c
@@ -968,6 +968,8 @@ void phy_stop(struct phy_device *phydev)
         * of rtnl_lock(), but PHY_HALTED shall guarantee phy_change()
         * will not reenable interrupts.
         */
+       if (phy_interrupt_is_valid(phydev))
+               phy_change(phydev);
 }
 EXPORT_SYMBOL(phy_stop);
-- 
Florian