On Mon, 15 Dec 2014 13:34:56 +0000 David Laight <David.Laight@xxxxxxxxxx> wrote: > From: Sergei Shtylyov > > Hello. > > > > On 12/15/2014 4:03 PM, Boris Brezillon wrote: > > > > > 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"); > > > } > > > > Looks like t make sense to read the INT_ENB register into a separate > > variable, to save on extra reads? > > > Better still remember the written value in one of the structures so > that it doesn't have to be read at all. Sure, I'll modify the code accordingly. Thanks, Boris -- Boris Brezillon, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html