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usb: gadget: atmel_usba_udc: Request an auto disabled Vbus signal IRQ

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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@finsecur.com>
Suggested-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
This commit is contained in:
Sylvain Rochet 2015-02-12 18:54:05 +01:00 committed by Felipe Balbi
parent 227ab58cff
commit bb0a203c3a
1 changed files with 2 additions and 7 deletions
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9
drivers/usb/gadget/udc/atmel_usba_udc.c
View file

@ -1749,10 +1749,6 @@ 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) {
@ -1773,7 +1769,6 @@ static irqreturn_t usba_vbus_irq(int irq, void *devid)
udc->vbus_prev = vbus;
}
out:
spin_unlock(&udc->lock);
return IRQ_HANDLED;
@ -2113,6 +2108,8 @@ 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);
ret = devm_request_irq(&pdev->dev,
gpio_to_irq(udc->vbus_pin),
usba_vbus_irq, 0,
@ -2122,8 +2119,6 @@ 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 */