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.roc...@finsecur.com>
Suggested-by: Boris Brezillon <boris.brezil...@free-electrons.com>
Acked-by: Boris Brezillon <boris.brezil...@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.fe...@atmel.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 e63c6fc..bbbd5f1 100644
--- a/drivers/usb/gadget/udc/atmel_usba_udc.c
+++ b/drivers/usb/gadget/udc/atmel_usba_udc.c
@@ -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 */
--
2.1.4
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