From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966059AbcIHO1z (ORCPT ); Thu, 8 Sep 2016 10:27:55 -0400 Received: from kozue.soulik.info ([108.61.200.231]:57812 "EHLO kozue.soulik.info" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965971AbcIHO1x (ORCPT ); Thu, 8 Sep 2016 10:27:53 -0400 From: Randy Li To: linux-usb@vger.kernel.org Cc: John.Youn@synopsys.com, kishon@ti.com, felipe.balbi@linux.intel.com, mark.rutland@arm.com, devicetree@vger.kernel.org, heiko@sntech.de, gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, linux-rockchip@lists.infradead.org, robh+dt@kernel.org, randy.li@rock-chips.com, Randy Li Subject: [PATCH 3/4] usb: dwc2: assert phy reset when waking up in rk3288 platform Date: Thu, 8 Sep 2016 22:27:15 +0800 Message-Id: <1473344836-26707-4-git-send-email-ayaka@soulik.info> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1473344836-26707-1-git-send-email-ayaka@soulik.info> References: <1473344836-26707-1-git-send-email-ayaka@soulik.info> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On the rk3288 USB host-only port (the one that's not the OTG-enabled port) the PHY can get into a bad state when a wakeup is asserted (not just a wakeup from full system suspend but also a wakeup from autosuspend). We can get the PHY out of its bad state by asserting its "port reset", but unfortunately that seems to assert a reset onto the USB bus so it could confuse things if we don't actually deenumerate / reenumerate the device. We can also get the PHY out of its bad state by fully resetting it using the reset from the CRU (clock reset unit) in chip, which does a more full reset. The CRU-based reset appears to actually cause devices on the bus to be removed and reinserted, which fixes the problem (albeit in a hacky way). It's unfortunate that we need to do a full re-enumeration of devices at wakeup time, but this is better than alternative of letting the bus get wedged. Signed-off-by: Randy Li --- drivers/usb/dwc2/core_intr.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/drivers/usb/dwc2/core_intr.c b/drivers/usb/dwc2/core_intr.c index d85c5c9..5b9b671 100644 --- a/drivers/usb/dwc2/core_intr.c +++ b/drivers/usb/dwc2/core_intr.c @@ -345,6 +345,7 @@ static void dwc2_handle_session_req_intr(struct dwc2_hsotg *hsotg) static void dwc2_handle_wakeup_detected_intr(struct dwc2_hsotg *hsotg) { int ret; + struct device_node *np = hsotg->dev->of_node; /* Clear interrupt */ dwc2_writel(GINTSTS_WKUPINT, hsotg->regs + GINTSTS); @@ -379,6 +380,16 @@ static void dwc2_handle_wakeup_detected_intr(struct dwc2_hsotg *hsotg) /* Restart the Phy Clock */ pcgcctl &= ~PCGCTL_STOPPCLK; dwc2_writel(pcgcctl, hsotg->regs + PCGCTL); + + /* + * It is a quirk in Rockchip RK3288, causing by + * a hardware bug. This will propagate out and + * eventually we'll re-enumerate the device. + * Not great but the best we can do + */ + if (of_device_is_compatible(np, "rockchip,rk3288-usb")) + phy_reset(hsotg->phy); + mod_timer(&hsotg->wkp_timer, jiffies + msecs_to_jiffies(71)); } else { -- 2.7.4