Re: [PATCH RfC 1/2] net: phy: core: remove now uneeded disabling of interrupts

[Heiner Kallweit <hkallweit1@gmail.com>]

Am 16.11.2017 um 10:51 schrieb Ard Biesheuvel:
> On 15 November 2017 at 22:19, Heiner Kallweit <hkallweit1@gmail.com> wrote:
>> Am 15.11.2017 um 23:04 schrieb Florian Fainelli:
>>> On 11/12/2017 01:08 PM, Heiner Kallweit wrote:
>>>> After commits c974bdbc3e "net: phy: Use threaded IRQ, to allow IRQ from
>>>> sleeping devices" and 664fcf123a30 "net: phy: Threaded interrupts allow
>>>> some simplification" all relevant code pieces run in process context
>>>> anyway and I don't think we need the disabling of interrupts any longer.
>>>>
>>>> Interestingly enough, latter commit already removed the comment
>>>> explaining why interrupts need to be temporarily disabled.
>>>>
>>>> On my system phy interrupt mode works fine with this patch.
>>>> However I may miss something, especially in the context of shared phy
>>>> interrupts, therefore I'd appreciate if more people could test this.
>>>
>>> I am not currently in a position to test this, but this looks very
>>> similar, if not identical to what Ard submitted a few days earlier:
>>>
>>
>> Thanks for the hint. Indeed it's exactly the same patch, so the one
>> sent by me can be disregarded.
>>
> 
> Well, it does appear your patch is more complete. Another difference
> is that I actually need this change to fix an issue with a
> hierarchical irqchip stacked on top of the GIC.
> 
> 
>>> https://patchwork.kernel.org/patch/10048901/
>>>
>>> Since net-next is closed at the moment, that should allow us to give
>>> this some good amount of testing.
>>>
>>> Thanks
>>>
>>>>
>>>> Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
> 
> For the record
> 
> Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> 
> Dear maintainers,
> 
> Please take whichever of these patches looks more correct to you.
> 
> Thanks,
> Ard.
> 

These two patches have status RFC in patchwork. Based on Ard's review
and comment, any action to be taken from his or my side?

Rgds, Heiner

>>>> ---
>>>>  drivers/net/phy/phy.c | 26 ++------------------------
>>>>  include/linux/phy.h   |  1 -
>>>>  2 files changed, 2 insertions(+), 25 deletions(-)
>>>>
>>>> diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
>>>> index 2b1e67bc1..b3784c9a2 100644
>>>> --- a/drivers/net/phy/phy.c
>>>> +++ b/drivers/net/phy/phy.c
>>>> @@ -629,9 +629,6 @@ static irqreturn_t phy_interrupt(int irq, void *phy_dat)
>>>>      if (PHY_HALTED == phydev->state)
>>>>              return IRQ_NONE;                /* It can't be ours.  */
>>>>
>>>> -    disable_irq_nosync(irq);
>>>> -    atomic_inc(&phydev->irq_disable);
>>>> -
>>>>      phy_change(phydev);
>>>>
>>>>      return IRQ_HANDLED;
>>>> @@ -689,7 +686,6 @@ static int phy_disable_interrupts(struct phy_device *phydev)
>>>>   */
>>>>  int phy_start_interrupts(struct phy_device *phydev)
>>>>  {
>>>> -    atomic_set(&phydev->irq_disable, 0);
>>>>      if (request_threaded_irq(phydev->irq, NULL, phy_interrupt,
>>>>                               IRQF_ONESHOT | IRQF_SHARED,
>>>>                               phydev_name(phydev), phydev) < 0) {
>>>> @@ -716,13 +712,6 @@ int phy_stop_interrupts(struct phy_device *phydev)
>>>>
>>>>      free_irq(phydev->irq, phydev);
>>>>
>>>> -    /* If work indeed has been cancelled, disable_irq() will have
>>>> -     * been left unbalanced from phy_interrupt() and enable_irq()
>>>> -     * has to be called so that other devices on the line work.
>>>> -     */
>>>> -    while (atomic_dec_return(&phydev->irq_disable) >= 0)
>>>> -            enable_irq(phydev->irq);
>>>> -
>>>>      return err;
>>>>  }
>>>>  EXPORT_SYMBOL(phy_stop_interrupts);
>>>> @@ -736,7 +725,7 @@ void phy_change(struct phy_device *phydev)
>>>>      if (phy_interrupt_is_valid(phydev)) {
>>>>              if (phydev->drv->did_interrupt &&
>>>>                  !phydev->drv->did_interrupt(phydev))
>>>> -                    goto ignore;
>>>> +                    return;
>>>>
>>>>              if (phy_disable_interrupts(phydev))
>>>>                      goto phy_err;
>>>> @@ -748,27 +737,16 @@ void phy_change(struct phy_device *phydev)
>>>>      mutex_unlock(&phydev->lock);
>>>>
>>>>      if (phy_interrupt_is_valid(phydev)) {
>>>> -            atomic_dec(&phydev->irq_disable);
>>>> -            enable_irq(phydev->irq);
>>>> -
>>>>              /* Reenable interrupts */
>>>>              if (PHY_HALTED != phydev->state &&
>>>>                  phy_config_interrupt(phydev, PHY_INTERRUPT_ENABLED))
>>>> -                    goto irq_enable_err;
>>>> +                    goto phy_err;
>>>>      }
>>>>
>>>>      /* reschedule state queue work to run as soon as possible */
>>>>      phy_trigger_machine(phydev, true);
>>>>      return;
>>>>
>>>> -ignore:
>>>> -    atomic_dec(&phydev->irq_disable);
>>>> -    enable_irq(phydev->irq);
>>>> -    return;
>>>> -
>>>> -irq_enable_err:
>>>> -    disable_irq(phydev->irq);
>>>> -    atomic_inc(&phydev->irq_disable);
>>>>  phy_err:
>>>>      phy_error(phydev);
>>>>  }
>>>> diff --git a/include/linux/phy.h b/include/linux/phy.h
>>>> index dc82a07cb..8a87e441f 100644
>>>> --- a/include/linux/phy.h
>>>> +++ b/include/linux/phy.h
>>>> @@ -468,7 +468,6 @@ struct phy_device {
>>>>      /* Interrupt and Polling infrastructure */
>>>>      struct work_struct phy_queue;
>>>>      struct delayed_work state_queue;
>>>> -    atomic_t irq_disable;
>>>>
>>>>      struct mutex lock;
>>>>
>>>>
>>>
>>>
>>
>