This is a note to let you know that I've just added the patch titled
usb: dwc3: Issue core soft reset before enabling run/stop
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
usb-dwc3-issue-core-soft-reset-before-enabling-run-s.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 6a32b4c0d10b6d9886f7ee3a89bf8ecaeaa7c68b
Author: Wesley Cheng <quic_wcheng@xxxxxxxxxxx>
Date: Tue Mar 15 18:13:58 2022 -0700
usb: dwc3: Issue core soft reset before enabling run/stop
[ Upstream commit 0066472de157439d58454f4a55786f1045ea5681 ]
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@xxxxxxxxxxxx>
Signed-off-by: Wesley Cheng <quic_wcheng@xxxxxxxxxxx>
Link: https://lore.kernel.org/r/20220316011358.3057-1-quic_wcheng@xxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Stable-dep-of: 040f2dbd2010 ("usb: dwc3: gadget: Avoid duplicate requests to enable Run/Stop")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index f4655665a1b5..a9c49b2ce511 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -227,7 +227,7 @@ 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 a93c61bc5a7d..f320b989abd2 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -1422,6 +1422,8 @@ 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 079919b85d87..b95fc2ae8074 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -2088,6 +2088,17 @@ 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);
}
