If the USB device is connected to a host, the CPU cannot be suspended or else the USB device appears to be disconnected from the host's point of view. Only after a "USB suspend" state has been entered (as set by the host) or the host is disconnected can the system safely be suspended: in both these states, the clock is stopped. As such, this patch associates a "wake lock" with the running clock of the UDC to keep the system awake as long as the host maintains the USB connection active. Signed-off-by: Jonas Bonn <jonas@xxxxxxxxxxx> CC: Cristian Birsan <cristian.birsan@xxxxxxxxxxxxx> CC: Felipe Balbi <balbi@xxxxxxxxxx> CC: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> CC: Nicolas Ferre <nicolas.ferre@xxxxxxxxxxxxx> CC: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx> CC: Ludovic Desroches <ludovic.desroches@xxxxxxxxxxxxx> CC: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx CC: linux-usb@xxxxxxxxxxxxxxx --- drivers/usb/gadget/udc/atmel_usba_udc.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/usb/gadget/udc/atmel_usba_udc.c b/drivers/usb/gadget/udc/atmel_usba_udc.c index 740cb9308a86..864d03c3c9db 100644 --- a/drivers/usb/gadget/udc/atmel_usba_udc.c +++ b/drivers/usb/gadget/udc/atmel_usba_udc.c @@ -1859,6 +1859,8 @@ static int start_clock(struct usba_udc *udc) if (udc->clocked) return 0; + pm_stay_awake(&udc->pdev->dev); + ret = clk_prepare_enable(udc->pclk); if (ret) return ret; @@ -1881,6 +1883,8 @@ static void stop_clock(struct usba_udc *udc) clk_disable_unprepare(udc->pclk); udc->clocked = false; + + pm_relax(&udc->pdev->dev); } static int usba_start(struct usba_udc *udc) -- 2.19.1
