From c40cf7705e13d288d900e044c0a2f756e9e4909a Mon Sep 17 00:00:00 2001 From: Douglas Anderson Date: Tue, 16 Apr 2019 14:53:49 -0700 Subject: [PATCH] usb: dwc2: optionally assert phy reset when waking up 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), 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: Douglas Anderson Signed-off-by: Yunzhi Li Signed-off-by: Felipe Balbi --- drivers/usb/dwc2/core.h | 8 ++++++++ drivers/usb/dwc2/core_intr.c | 12 ++++++++++++ drivers/usb/dwc2/hcd.c | 18 +++++++++++++++--- drivers/usb/dwc2/platform.c | 9 +++++++++ 4 files changed, 44 insertions(+), 3 deletions(-) diff --git a/drivers/usb/dwc2/core.h b/drivers/usb/dwc2/core.h index 30bab8463c96..764c78ebee28 100644 --- a/drivers/usb/dwc2/core.h +++ b/drivers/usb/dwc2/core.h @@ -859,6 +859,8 @@ struct dwc2_hregs_backup { * @gadget_enabled: Peripheral mode sub-driver initialization indicator. * @ll_hw_enabled: Status of low-level hardware resources. * @hibernated: True if core is hibernated + * @reset_phy_on_wake: Quirk saying that we should assert PHY reset on a + * remote wakeup. * @frame_number: Frame number read from the core. For both device * and host modes. The value ranges are from 0 * to HFNUM_MAX_FRNUM. @@ -972,6 +974,7 @@ struct dwc2_hregs_backup { * @status_buf_dma: DMA address for status_buf * @start_work: Delayed work for handling host A-cable connection * @reset_work: Delayed work for handling a port reset + * @phy_reset_work: Work structure for doing a PHY reset * @otg_port: OTG port number * @frame_list: Frame list * @frame_list_dma: Frame list DMA address @@ -1045,6 +1048,7 @@ struct dwc2_hsotg { unsigned int gadget_enabled:1; unsigned int ll_hw_enabled:1; unsigned int hibernated:1; + unsigned int reset_phy_on_wake:1; u16 frame_number; struct phy *phy; @@ -1147,6 +1151,7 @@ struct dwc2_hsotg { struct delayed_work start_work; struct delayed_work reset_work; + struct work_struct phy_reset_work; u8 otg_port; u32 *frame_list; dma_addr_t frame_list_dma; @@ -1431,6 +1436,8 @@ int dwc2_restore_host_registers(struct dwc2_hsotg *hsotg); int dwc2_host_enter_hibernation(struct dwc2_hsotg *hsotg); int dwc2_host_exit_hibernation(struct dwc2_hsotg *hsotg, int rem_wakeup, int reset); +static inline void dwc2_host_schedule_phy_reset(struct dwc2_hsotg *hsotg) +{ schedule_work(&hsotg->phy_reset_work); } #else static inline int dwc2_hcd_get_frame_number(struct dwc2_hsotg *hsotg) { return 0; } @@ -1454,6 +1461,7 @@ static inline int dwc2_host_enter_hibernation(struct dwc2_hsotg *hsotg) static inline int dwc2_host_exit_hibernation(struct dwc2_hsotg *hsotg, int rem_wakeup, int reset) { return 0; } +static inline void dwc2_host_schedule_phy_reset(struct dwc2_hsotg *hsotg) {} #endif diff --git a/drivers/usb/dwc2/core_intr.c b/drivers/usb/dwc2/core_intr.c index 19ae2595f1c3..6af6add3d4c0 100644 --- a/drivers/usb/dwc2/core_intr.c +++ b/drivers/usb/dwc2/core_intr.c @@ -435,6 +435,18 @@ static void dwc2_handle_wakeup_detected_intr(struct dwc2_hsotg *hsotg) /* Restart the Phy Clock */ pcgcctl &= ~PCGCTL_STOPPCLK; dwc2_writel(hsotg, pcgcctl, PCGCTL); + + /* + * If we've got this quirk then the PHY is stuck upon + * wakeup. Assert reset. This will propagate out and + * eventually we'll re-enumerate the device. Not great + * but the best we can do. We can't call phy_reset() + * at interrupt time but there's no hurry, so we'll + * schedule it for later. + */ + if (hsotg->reset_phy_on_wake) + dwc2_host_schedule_phy_reset(hsotg); + mod_timer(&hsotg->wkp_timer, jiffies + msecs_to_jiffies(71)); } else { diff --git a/drivers/usb/dwc2/hcd.c b/drivers/usb/dwc2/hcd.c index 8667ddf3ca74..978232a9e4a8 100644 --- a/drivers/usb/dwc2/hcd.c +++ b/drivers/usb/dwc2/hcd.c @@ -4376,6 +4376,17 @@ static void dwc2_hcd_reset_func(struct work_struct *work) spin_unlock_irqrestore(&hsotg->lock, flags); } +static void dwc2_hcd_phy_reset_func(struct work_struct *work) +{ + struct dwc2_hsotg *hsotg = container_of(work, struct dwc2_hsotg, + phy_reset_work); + int ret; + + ret = phy_reset(hsotg->phy); + if (ret) + dev_warn(hsotg->dev, "PHY reset failed\n"); +} + /* * ========================================================================= * Linux HC Driver Functions @@ -5152,6 +5163,8 @@ static void dwc2_hcd_free(struct dwc2_hsotg *hsotg) destroy_workqueue(hsotg->wq_otg); } + cancel_work_sync(&hsotg->phy_reset_work); + del_timer(&hsotg->wkp_timer); } @@ -5293,11 +5306,10 @@ int dwc2_hcd_init(struct dwc2_hsotg *hsotg) hsotg->hc_ptr_array[i] = channel; } - /* Initialize hsotg start work */ + /* Initialize work */ INIT_DELAYED_WORK(&hsotg->start_work, dwc2_hcd_start_func); - - /* Initialize port reset work */ INIT_DELAYED_WORK(&hsotg->reset_work, dwc2_hcd_reset_func); + INIT_WORK(&hsotg->phy_reset_work, dwc2_hcd_phy_reset_func); /* * Allocate space for storing data on status transactions. Normally no diff --git a/drivers/usb/dwc2/platform.c b/drivers/usb/dwc2/platform.c index 9aa9682a5cd2..c01fa8ffc0c8 100644 --- a/drivers/usb/dwc2/platform.c +++ b/drivers/usb/dwc2/platform.c @@ -481,6 +481,15 @@ static int dwc2_driver_probe(struct platform_device *dev) hsotg->gadget_enabled = 1; } + hsotg->reset_phy_on_wake = + of_property_read_bool(dev->dev.of_node, + "snps,reset-phy-on-wake"); + if (hsotg->reset_phy_on_wake && !hsotg->phy) { + dev_warn(hsotg->dev, + "Quirk reset-phy-on-wake only supports generic PHYs\n"); + hsotg->reset_phy_on_wake = false; + } + if (hsotg->dr_mode != USB_DR_MODE_PERIPHERAL) { retval = dwc2_hcd_init(hsotg); if (retval) { -- 2.11.0