[PATCH v2 4/5] usb: atmel_usba_udc: Mask status with enabled irqs

From: Boris Brezillon
Date: Tue Jan 06 2015 - 08:48:20 EST


Avoid interpreting useless status flags when we're not waiting for such
events by masking the status variable with the interrupt enabled register
value.

Reported-by: Patrice VILCHEZ <patrice.vilchez@xxxxxxxxx>
Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxxxxxxx>
---
drivers/usb/gadget/udc/atmel_usba_udc.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/gadget/udc/atmel_usba_udc.c b/drivers/usb/gadget/udc/atmel_usba_udc.c
index 55c8dde..bc3a532 100644
--- a/drivers/usb/gadget/udc/atmel_usba_udc.c
+++ b/drivers/usb/gadget/udc/atmel_usba_udc.c
@@ -1612,12 +1612,14 @@ static irqreturn_t usba_udc_irq(int irq, void *devid)

spin_lock(&udc->lock);

- status = usba_readl(udc, INT_STA);
+ status = usba_readl(udc, INT_STA) & usba_readl(udc, INT_ENB);
DBG(DBG_INT, "irq, status=%#08x\n", status);

if (status & USBA_DET_SUSPEND) {
toggle_bias(udc, 0);
usba_writel(udc, INT_CLR, USBA_DET_SUSPEND);
+ usba_writel(udc, INT_ENB,
+ usba_readl(udc, INT_ENB) | USBA_WAKE_UP);
udc->bias_pulse_needed = true;
DBG(DBG_BUS, "Suspend detected\n");
if (udc->gadget.speed != USB_SPEED_UNKNOWN
@@ -1631,6 +1633,8 @@ static irqreturn_t usba_udc_irq(int irq, void *devid)
if (status & USBA_WAKE_UP) {
toggle_bias(udc, 1);
usba_writel(udc, INT_CLR, USBA_WAKE_UP);
+ usba_writel(udc, INT_ENB,
+ usba_readl(udc, INT_ENB) & ~USBA_WAKE_UP);
DBG(DBG_BUS, "Wake Up CPU detected\n");
}

--
1.9.1

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