[PATCHv6 2/5] USB: gadget: atmel_usba_udc: Request an auto disabled Vbus signal IRQ instead of an auto enabled IRQ request followed by IRQ disable
Nicolas Ferre
nicolas.ferre at atmel.com
Fri Jan 23 00:59:58 PST 2015
Le 23/01/2015 08:43, Jean-Christophe PLAGNIOL-VILLARD a écrit :
>
>> On Jan 23, 2015, at 12:56 AM, Sylvain Rochet <sylvain.rochet at finsecur.com> wrote:
>>
>> Vbus IRQ handler needs a started UDC driver to work because it uses
>> udc->driver, which is set by the UDC start handler. The previous way
>> chosen was to return from interrupt if udc->driver is NULL using a
>> spinlock around the check.
>>
>> We now request an auto disabled (IRQ_NOAUTOEN) Vbus signal IRQ instead
>> of an auto enabled IRQ followed by disable_irq(). This way we remove the
>> very small timeslot of enabled IRQ which existed previously between
>> request() and disable(). We don't need anymore to check if udc->driver
>> is NULL in IRQ handler.
>>
>> Signed-off-by: Sylvain Rochet <sylvain.rochet at finsecur.com>
>> Suggested-by: Boris Brezillon <boris.brezillon at free-electrons.com>
>> Acked-by: Boris Brezillon <boris.brezillon at free-electrons.com>
>> ---
>> drivers/usb/gadget/udc/atmel_usba_udc.c | 9 ++-------
>> 1 file changed, 2 insertions(+), 7 deletions(-)
>>
>> diff --git a/drivers/usb/gadget/udc/atmel_usba_udc.c b/drivers/usb/gadget/udc/atmel_usba_udc.c
>> index 40e5fc7..f9f305f 100644
>> --- a/drivers/usb/gadget/udc/atmel_usba_udc.c
>> +++ b/drivers/usb/gadget/udc/atmel_usba_udc.c
>> @@ -1745,10 +1745,6 @@ static irqreturn_t usba_vbus_irq(int irq, void *devid)
>>
>> spin_lock(&udc->lock);
>>
>> - /* May happen if Vbus pin toggles during probe() */
>> - if (!udc->driver)
>> - goto out;
>> -
>> vbus = vbus_is_present(udc);
>> if (vbus != udc->vbus_prev) {
>> if (vbus) {
>> @@ -1769,7 +1765,6 @@ static irqreturn_t usba_vbus_irq(int irq, void *devid)
>> udc->vbus_prev = vbus;
>> }
>>
>> -out:
>> spin_unlock(&udc->lock);
>>
>> return IRQ_HANDLED;
>> @@ -2109,6 +2104,8 @@ static int usba_udc_probe(struct platform_device *pdev)
>>
>> if (gpio_is_valid(udc->vbus_pin)) {
>> if (!devm_gpio_request(&pdev->dev, udc->vbus_pin, "atmel_usba_udc")) {
>> + irq_set_status_flags(gpio_to_irq(udc->vbus_pin),
>> + IRQ_NOAUTOEN);
>
> not happy about still using the broken gpio_to_irq API
>
> Linus can pass the IRQ via board file?
>
> and via DT we can use IRQ directly
Absolutely not the topic of this patch series.
Maybe the subject of another patch later?
Best regards,
>> ret = devm_request_irq(&pdev->dev,
>> gpio_to_irq(udc->vbus_pin),
>> usba_vbus_irq, 0,
>> @@ -2118,8 +2115,6 @@ static int usba_udc_probe(struct platform_device *pdev)
>> dev_warn(&udc->pdev->dev,
>> "failed to request vbus irq; "
>> "assuming always on\n");
>> - } else {
>> - disable_irq(gpio_to_irq(udc->vbus_pin));
>> }
>> } else {
>> /* gpio_request fail so use -EINVAL for gpio_is_valid */
>> --
>> 2.1.4
>>
>>
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>
>
--
Nicolas Ferre
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