From 0066472de157439d58454f4a55786f1045ea5681 Mon Sep 17 00:00:00 2001
From: Wesley Cheng <quic_wcheng@quicinc.com>
Date: Tue, 15 Mar 2022 18:13:58 -0700
Subject: [PATCH] usb: dwc3: Issue core soft reset before enabling run/stop
Git-commit: 0066472de157439d58454f4a55786f1045ea5681
References: git-fixes
Patch-mainline: v5.18-rc1
It is recommended by the Synopsis databook to issue a DCTL.CSftReset
when reconnecting from a device-initiated disconnect routine. This
resolves issues with enumeration during fast composition switching
cases, which result in an unknown device on the host.
Reviewed-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
Link: https://lore.kernel.org/r/20220316011358.3057-1-quic_wcheng@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Oliver Neukum <oneukum@suse.com>
---
drivers/usb/dwc3/core.c | 4 +---
drivers/usb/dwc3/core.h | 2 ++
drivers/usb/dwc3/gadget.c | 11 +++++++++++
3 files changed, 14 insertions(+), 3 deletions(-)
diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 416d83a055fe..1170b800acdc 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -115,8 +115,6 @@ void dwc3_set_prtcap(struct dwc3 *dwc, u32 mode)
dwc->current_dr_role = mode;
}
-static int dwc3_core_soft_reset(struct dwc3 *dwc);
-
static void __dwc3_set_mode(struct work_struct *work)
{
struct dwc3 *dwc = work_to_dwc(work);
@@ -261,7 +259,7 @@ u32 dwc3_core_fifo_space(struct dwc3_ep *dep, u8 type)
* dwc3_core_soft_reset - Issues core soft reset and PHY reset
* @dwc: pointer to our context structure
*/
-static int dwc3_core_soft_reset(struct dwc3 *dwc)
+int dwc3_core_soft_reset(struct dwc3 *dwc)
{
u32 reg;
int retries = 1000;
diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index e9b1e9b8f1f3..5c9d467195a6 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -1532,6 +1532,8 @@ bool dwc3_has_imod(struct dwc3 *dwc);
int dwc3_event_buffers_setup(struct dwc3 *dwc);
void dwc3_event_buffers_cleanup(struct dwc3 *dwc);
+int dwc3_core_soft_reset(struct dwc3 *dwc);
+
#if IS_ENABLED(CONFIG_USB_DWC3_HOST) || IS_ENABLED(CONFIG_USB_DWC3_DUAL_ROLE)
int dwc3_host_init(struct dwc3 *dwc);
void dwc3_host_exit(struct dwc3 *dwc);
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 2a96826b7efd..ab725d2262d6 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -2578,6 +2578,17 @@ static int dwc3_gadget_pullup(struct usb_gadget *g, int is_on)
dwc->ev_buf->length;
}
} else {
+ /*
+ * In the Synopsys DWC_usb31 1.90a programming guide section
+ * 4.1.9, it specifies that for a reconnect after a
+ * device-initiated disconnect requires a core soft reset
+ * (DCTL.CSftRst) before enabling the run/stop bit.
+ */
+ spin_unlock_irqrestore(&dwc->lock, flags);
+ dwc3_core_soft_reset(dwc);
+ spin_lock_irqsave(&dwc->lock, flags);
+
+ dwc3_event_buffers_setup(dwc);
__dwc3_gadget_start(dwc);
}
--
2.35.3