From c74ab90e7b8e0d663c85107566080de0ce72a9ff Mon Sep 17 00:00:00 2001 From: Jacob Chen Date: Wed, 7 Dec 2016 17:29:06 +0800 Subject: [PATCH] FROMLIST: usb: dwc2: assert phy reset when waking up in rk3288 platform 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. Change-Id: I3120a38a7f646a9d244f04bd2dcfef7474a4a6d1 Signed-off-by: Randy Li Signed-off-by: Jacob Chen (am from https://mail-archive.com/linux-kernel@vger.kernel.org/msg1254059.html) --- drivers/usb/dwc2/core.h | 1 + drivers/usb/dwc2/core_intr.c | 13 +++++++++++++ drivers/usb/dwc2/platform.c | 9 +++++++++ 3 files changed, 23 insertions(+) diff --git a/drivers/usb/dwc2/core.h b/drivers/usb/dwc2/core.h index 907da681930a..eda4522be239 100644 --- a/drivers/usb/dwc2/core.h +++ b/drivers/usb/dwc2/core.h @@ -739,6 +739,7 @@ struct dwc2_hsotg { unsigned int ll_hw_enabled:1; struct phy *phy; + struct work_struct phy_rst_work; struct usb_phy *uphy; struct dwc2_hsotg_plat *plat; struct regulator_bulk_data supplies[ARRAY_SIZE(dwc2_hsotg_supply_names)]; diff --git a/drivers/usb/dwc2/core_intr.c b/drivers/usb/dwc2/core_intr.c index 27daa42788b1..93309d7452ed 100644 --- a/drivers/usb/dwc2/core_intr.c +++ b/drivers/usb/dwc2/core_intr.c @@ -347,6 +347,7 @@ 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; dev_dbg(hsotg->dev, "++Resume or Remote Wakeup Detected Interrupt++\n"); dev_dbg(hsotg->dev, "%s lxstate = %d\n", __func__, hsotg->lx_state); @@ -378,6 +379,18 @@ 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")) { + /* FIXME: wkp_timer might run early than phy_rst_work */ + schedule_work(&hsotg->phy_rst_work); + } + mod_timer(&hsotg->wkp_timer, jiffies + msecs_to_jiffies(71)); } else { diff --git a/drivers/usb/dwc2/platform.c b/drivers/usb/dwc2/platform.c index 00b3ae0e7191..b8ed6766919e 100644 --- a/drivers/usb/dwc2/platform.c +++ b/drivers/usb/dwc2/platform.c @@ -202,6 +202,14 @@ int dwc2_lowlevel_hw_disable(struct dwc2_hsotg *hsotg) return ret; } +/* Only used to reset usb phy at interrupter runtime */ +static void dwc2_reset_phy_work(struct work_struct *data) +{ + struct dwc2_hsotg *hsotg = container_of(data, struct dwc2_hsotg, + phy_rst_work); + phy_reset(hsotg->phy); +} + static int dwc2_lowlevel_hw_init(struct dwc2_hsotg *hsotg) { int i, ret; @@ -228,6 +236,7 @@ static int dwc2_lowlevel_hw_init(struct dwc2_hsotg *hsotg) return ret; } } + INIT_WORK(&hsotg->phy_rst_work, dwc2_reset_phy_work); if (!hsotg->phy) { hsotg->uphy = devm_usb_get_phy(hsotg->dev, USB_PHY_TYPE_USB2); -- 2.34.1