On 12.02.2019 20:37, Andrew Lunn wrote:
> On Tue, Feb 12, 2019 at 07:56:15PM +0100, Heiner Kallweit wrote:
>> phylib enables interrupts before phy_start() has been called, and if
>> we receive an interrupt in a non-started state, the interrupt handler
>> returns IRQ_NONE. This causes problems with at least one Marvell chip
>> as reported by Andrew.
>> Fix this by handling interrupts the same as in phy_mac_interrupt(),
>> basically always running the phylib state machine. It knows when it
>> has to do something and when not.
>> This change allows to handle interrupts gracefully even if they
>> occur in a non-started state.
>>
>> Fixes: 2b3e88ea6528 ("net: phy: improve phy state checking")
>> Reported-by: Andrew Lunn <and...@lunn.ch>
>> Signed-off-by: Heiner Kallweit <hkallwe...@gmail.com>
>> ---
>> drivers/net/phy/phy.c | 3 ---
>> 1 file changed, 3 deletions(-)
>>
>> diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
>> index 189cd2048c3a..ca5e0c0f018c 100644
>> --- a/drivers/net/phy/phy.c
>> +++ b/drivers/net/phy/phy.c
>> @@ -762,9 +762,6 @@ static irqreturn_t phy_interrupt(int irq, void *phy_dat)
>> {
>> struct phy_device *phydev = phy_dat;
>>
>> - if (!phy_is_started(phydev))
>> - return IRQ_NONE; /* It can't be ours. */
>> -
>> if (phydev->drv->did_interrupt && !phydev->drv->did_interrupt(phydev))
>> return IRQ_NONE;
>
> Hi Heiner
>
> Did you look at
>
Thanks for this interesting old read.
> ommit 3c3070d713d798f7f9e7ee3614e49b47655d14d8
> Author: Maciej W. Rozycki <ma...@linux-mips.org>
> Date: Tue Oct 3 16:18:35 2006 +0100
>
> [PATCH] 2.6.18: sb1250-mac: Phylib IRQ handling fixes
>
> This patch fixes a couple of problems discovered with interrupt handling
> in the phylib core, namely:
>
> 1. The driver uses timer and workqueue calls, but does not include
> <linux/timer.h> nor <linux/workqueue.h>.
>
> 2. The driver uses schedule_work() for handling interrupts, but does not
> make sure any pending work scheduled thus has been completed before
> driver's structures get freed from memory. This is especially
> important as interrupts may keep arriving if the line is shared with
> another PHY.
>
Since that time this have massively changed and I *think* this doesn't apply
any longer. cancel_delayed_work_sync() is called always before driver
structure is freed.
> The solution is to ignore phy_interrupt() calls if the reported device
> has already been halted and calling flush_scheduled_work() from
> phy_stop_interrupts() (but guarded with current_is_keventd() in case
> the function has been called through keventd from the MAC device's
> close call to avoid a deadlock on the netlink lock).
>
> Signed-off-by: Maciej W. Rozycki <ma...@linux-mips.org>
>
> patch-mips-2.6.18-20060920-phy-irq-16
> Signed-off-by: Jeff Garzik <j...@garzik.org>
>
> There has been a lot of change since then, so maybe this is no longer
> an issue?
>
AFAICS, yes. I'll have a closer look at the scenario described by Russell,
this however should be independent of the patch here.
> Thanks
> Andrew
>
Heiner
