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SubjectRe: [linux-next][PATCH] usb: dwc3: omap: remove IRQ_NOAUTOEN used with shared irq
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Hi,

On Saturday 01 July 2017 01:04 AM, Strashko, Grygorii wrote:
>
>
> On 06/29/2017 01:03 AM, Tony Lindgren wrote:
>> * Vignesh R <vigneshr@ti.com> [170628 21:21]:
>>>
>>>
>>> On Thursday 29 June 2017 05:01 AM, Strashko, Grygorii wrote:
>>>> IRQ_NOAUTOEN can't be used with shared IRQs and Kernel now will triggers
>>>> warning if it happns, since commit 04c848d39879 ("genirq: Warn when
>>>> IRQ_NOAUTOEN is used with shared interrupts"). And this is the case for
>>>> OMAP DWC 3 driver.
>>>>
>>>> Hence, remove IRQ_NOAUTOEN flag and instead call disable_irq() before
>>>> disabling PM runtime in probe error path handling.
>>>
>>> Or, how about requesting the irq at the end of probe after extcon
>>> registration?
>>
>> Hmm yeah, what prevents the issue that we tried to fix with commit
>> 12a7f17fac5b ("usb: dwc3: omap: fix race of pm runtime with irq handler
>> in probe")?
>
> No, I think. There should be the disable_irq() call any way
> before pm_runtime_put_sync(dev);| pm_runtime_disable(dev); -
> once IRQ is requested driver can't know if IRQ handler is running now or not
> unless it will call disable_irq()/free_irq().
>
> But, I've also thought about moving request_irq() down (seems
> it can be moved even after of_platform_populate()).
> looks like it can be separate patch.
>

commit 12a7f17fac5b says PM runtime can race with IRQ handler when
deferred probing happening due to extcon, therefore IRQ_NOAUTOEN was set
and disable_irq() call was added. If IRQ handler registration is moved
to a place after of_platform_populate(), then we can be sure that extcon
is registered and there wont be any deferred probe or race with irq
handler and PM runtime. Would disable_irq() still be needed then?

>
>>>> Fixes: 12a7f17fac5b ("usb: dwc3: omap: fix race of pm runtime with...")
>>>> Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
>>>> ---
>>>> drivers/usb/dwc3/dwc3-omap.c | 3 +--
>>>> 1 file changed, 1 insertion(+), 2 deletions(-)
>>>>
>>>> diff --git a/drivers/usb/dwc3/dwc3-omap.c b/drivers/usb/dwc3/dwc3-omap.c
>>>> index 9892650..cd9bef5 100644
>>>> --- a/drivers/usb/dwc3/dwc3-omap.c
>>>> +++ b/drivers/usb/dwc3/dwc3-omap.c
>>>> @@ -512,7 +512,6 @@ static int dwc3_omap_probe(struct platform_device *pdev)
>>>>
>>>> /* check the DMA Status */
>>>> reg = dwc3_omap_readl(omap->base, USBOTGSS_SYSCONFIG);
>>>> - irq_set_status_flags(omap->irq, IRQ_NOAUTOEN);
>>>> ret = devm_request_threaded_irq(dev, omap->irq, dwc3_omap_interrupt,
>>>> dwc3_omap_interrupt_thread, IRQF_SHARED,
>>>> "dwc3-omap", omap);
>>>> @@ -533,10 +532,10 @@ static int dwc3_omap_probe(struct platform_device *pdev)
>>>> }
>>>>
>>>> dwc3_omap_enable_irqs(omap);
>>>> - enable_irq(omap->irq);
>>>> return 0;
>>>>
>>>> err1:
>>>> + disable_irq(omap->irq);
>>>> pm_runtime_put_sync(dev);
>>>> pm_runtime_disable(dev);
>>>>
>

--
Regards
Vignesh

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