From: Peter Chen Date: Tue, 1 Sep 2020 02:33:49 +0000 (+0800) Subject: usb: cdns3: gadget: set fast access bit X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=b5148d946f45bb7a780c2dc45a20f5b47e73f995;p=linux.git usb: cdns3: gadget: set fast access bit Below is the recommendation from Cadence designer: Using this bit to be sure that PHY clock is keeping up in active state. It's good to keep Fast Access bit enabled as long as there is any access to USB register. It is used to fix the potential ARM core hang when visit controller register after DEVDS (.pullup is cleared) is set, the threaded irq may be scheduled at that time. Cc: Pawel Laszczak Reviewed-by: Jun Li Signed-off-by: Peter Chen Signed-off-by: Felipe Balbi --- diff --git a/drivers/usb/cdns3/gadget.c b/drivers/usb/cdns3/gadget.c index 9e6ff7d00784a..081447bf73134 100644 --- a/drivers/usb/cdns3/gadget.c +++ b/drivers/usb/cdns3/gadget.c @@ -2783,6 +2783,8 @@ static void cdns3_gadget_config(struct cdns3_device *priv_dev) /* enable generic interrupt*/ writel(USB_IEN_INIT, ®s->usb_ien); writel(USB_CONF_CLK2OFFDS | USB_CONF_L1DS, ®s->usb_conf); + /* keep Fast Access bit */ + writel(PUSB_PWR_FST_REG_ACCESS, &priv_dev->regs->usb_pwr); cdns3_configure_dmult(priv_dev, NULL); } @@ -2866,6 +2868,7 @@ static int cdns3_gadget_udc_stop(struct usb_gadget *gadget) /* disable interrupt for device */ writel(0, &priv_dev->regs->usb_ien); + writel(0, &priv_dev->regs->usb_pwr); writel(USB_CONF_DEVDS, &priv_dev->regs->usb_conf); return 0;