Patch "usb: dwc3: fix gadget mode suspend interrupt handler issue" has been added to the 5.15-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    usb: dwc3: fix gadget mode suspend interrupt handler issue

to the 5.15-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-fix-gadget-mode-suspend-interrupt-handler-i.patch
and it can be found in the queue-5.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 7335e0994a28b1167e2549fc5c0331d6bdf31df1
Author: Linyu Yuan <quic_linyyuan@xxxxxxxxxxx>
Date:   Fri May 12 08:45:24 2023 +0800

    usb: dwc3: fix gadget mode suspend interrupt handler issue
    
    [ Upstream commit 4e8ef34e36f2839ef8c8da521ab7035956436818 ]
    
    When work in gadget mode, currently driver doesn't update software level
    link_state correctly as link state change event is not enabled for most
    devices, in function dwc3_gadget_suspend_interrupt(), it will only pass
    suspend event to UDC core when software level link state changes, so when
    interrupt generated in sequences of suspend -> reset -> conndone ->
    suspend, link state is not updated during reset and conndone, so second
    suspend interrupt event will not pass to UDC core.
    
    Remove link_state compare in dwc3_gadget_suspend_interrupt() and add a
    suspended flag to replace the compare function.
    
    Fixes: 799e9dc82968 ("usb: dwc3: gadget: conditionally disable Link State change events")
    Cc: stable <stable@xxxxxxxxxx>
    Acked-by: Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx>
    Signed-off-by: Linyu Yuan <quic_linyyuan@xxxxxxxxxxx>
    Link: https://lore.kernel.org/r/20230512004524.31950-1-quic_linyyuan@xxxxxxxxxxx
    Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index 725653711411d..84cdac33cb359 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -1085,6 +1085,7 @@ struct dwc3_scratchpad_array {
  *	3	- Reserved
  * @dis_metastability_quirk: set to disable metastability quirk.
  * @dis_split_quirk: set to disable split boundary.
+ * @suspended: set to track suspend event due to U3/L2.
  * @imod_interval: set the interrupt moderation interval in 250ns
  *			increments or 0 to disable.
  * @max_cfg_eps: current max number of IN eps used across all USB configs.
@@ -1298,6 +1299,7 @@ struct dwc3 {
 
 	unsigned		dis_split_quirk:1;
 	unsigned		async_callbacks:1;
+	unsigned		suspended:1;
 
 	u16			imod_interval;
 
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 7ff77a0de5152..e42d50e4aba30 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -3694,6 +3694,8 @@ static void dwc3_gadget_disconnect_interrupt(struct dwc3 *dwc)
 {
 	int			reg;
 
+	dwc->suspended = false;
+
 	dwc3_gadget_set_link_state(dwc, DWC3_LINK_STATE_RX_DET);
 
 	reg = dwc3_readl(dwc->regs, DWC3_DCTL);
@@ -3714,6 +3716,8 @@ static void dwc3_gadget_reset_interrupt(struct dwc3 *dwc)
 {
 	u32			reg;
 
+	dwc->suspended = false;
+
 	/*
 	 * Ideally, dwc3_reset_gadget() would trigger the function
 	 * drivers to stop any active transfers through ep disable.
@@ -3919,6 +3923,8 @@ static void dwc3_gadget_conndone_interrupt(struct dwc3 *dwc)
 
 static void dwc3_gadget_wakeup_interrupt(struct dwc3 *dwc)
 {
+	dwc->suspended = false;
+
 	/*
 	 * TODO take core out of low power mode when that's
 	 * implemented.
@@ -4034,8 +4040,10 @@ static void dwc3_gadget_suspend_interrupt(struct dwc3 *dwc,
 {
 	enum dwc3_link_state next = evtinfo & DWC3_LINK_STATE_MASK;
 
-	if (dwc->link_state != next && next == DWC3_LINK_STATE_U3)
+	if (!dwc->suspended && next == DWC3_LINK_STATE_U3) {
+		dwc->suspended = true;
 		dwc3_suspend_gadget(dwc);
+	}
 
 	dwc->link_state = next;
 }