The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x 2372f1caeca433c4c01c2482f73fbe057f5168ce # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2025051215-spiffy-repost-d6d8@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 2372f1caeca433c4c01c2482f73fbe057f5168ce Mon Sep 17 00:00:00 2001 From: Prashanth K prashanth.k@oss.qualcomm.com Date: Tue, 22 Apr 2025 16:02:31 +0530 Subject: [PATCH] usb: dwc3: gadget: Make gadget_wakeup asynchronous
Currently gadget_wakeup() waits for U0 synchronously if it was called from func_wakeup(), this is because we need to send the function wakeup command soon after the link is active. And the call is made synchronous by polling DSTS continuosly for 20000 times in __dwc3_gadget_wakeup(). But it observed that sometimes the link is not active even after polling 20K times, leading to remote wakeup failures. Adding a small delay between each poll helps, but that won't guarantee resolution in future. Hence make the gadget_wakeup completely asynchronous.
Since multiple interfaces can issue a function wakeup at once, add a new variable wakeup_pending_funcs which will indicate the functions that has issued func_wakup, this is represented in a bitmap format. If the link is in U3, dwc3_gadget_func_wakeup() will set the bit corresponding to interface_id and bail out. Once link comes back to U0, linksts_change irq is triggered, where the function wakeup command is sent based on bitmap.
Cc: stable stable@kernel.org Fixes: 92c08a84b53e ("usb: dwc3: Add function suspend and function wakeup support") Signed-off-by: Prashanth K prashanth.k@oss.qualcomm.com Acked-by: Thinh Nguyen Thinh.Nguyen@synopsys.com Link: https://lore.kernel.org/r/20250422103231.1954387-4-prashanth.k@oss.qualcomm.... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h index aaa39e663f60..27eae4cf223d 100644 --- a/drivers/usb/dwc3/core.h +++ b/drivers/usb/dwc3/core.h @@ -1164,6 +1164,9 @@ struct dwc3_scratchpad_array { * @gsbuscfg0_reqinfo: store GSBUSCFG0.DATRDREQINFO, DESRDREQINFO, * DATWRREQINFO, and DESWRREQINFO value passed from * glue driver. + * @wakeup_pending_funcs: Indicates whether any interface has requested for + * function wakeup in bitmap format where bit position + * represents interface_id. */ struct dwc3 { struct work_struct drd_work; @@ -1394,6 +1397,7 @@ struct dwc3 { int num_ep_resized; struct dentry *debug_root; u32 gsbuscfg0_reqinfo; + u32 wakeup_pending_funcs; };
#define INCRX_BURST_MODE 0 diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index 8c30d86cc4e3..321361288935 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -276,8 +276,6 @@ int dwc3_send_gadget_generic_command(struct dwc3 *dwc, unsigned int cmd, return ret; }
-static int __dwc3_gadget_wakeup(struct dwc3 *dwc, bool async); - /** * dwc3_send_gadget_ep_cmd - issue an endpoint command * @dep: the endpoint to which the command is going to be issued @@ -2359,10 +2357,8 @@ static int dwc3_gadget_get_frame(struct usb_gadget *g) return __dwc3_gadget_get_frame(dwc); }
-static int __dwc3_gadget_wakeup(struct dwc3 *dwc, bool async) +static int __dwc3_gadget_wakeup(struct dwc3 *dwc) { - int retries; - int ret; u32 reg;
@@ -2390,8 +2386,7 @@ static int __dwc3_gadget_wakeup(struct dwc3 *dwc, bool async) return -EINVAL; }
- if (async) - dwc3_gadget_enable_linksts_evts(dwc, true); + dwc3_gadget_enable_linksts_evts(dwc, true);
ret = dwc3_gadget_set_link_state(dwc, DWC3_LINK_STATE_RECOV); if (ret < 0) { @@ -2410,27 +2405,8 @@ static int __dwc3_gadget_wakeup(struct dwc3 *dwc, bool async)
/* * Since link status change events are enabled we will receive - * an U0 event when wakeup is successful. So bail out. + * an U0 event when wakeup is successful. */ - if (async) - return 0; - - /* poll until Link State changes to ON */ - retries = 20000; - - while (retries--) { - reg = dwc3_readl(dwc->regs, DWC3_DSTS); - - /* in HS, means ON */ - if (DWC3_DSTS_USBLNKST(reg) == DWC3_LINK_STATE_U0) - break; - } - - if (DWC3_DSTS_USBLNKST(reg) != DWC3_LINK_STATE_U0) { - dev_err(dwc->dev, "failed to send remote wakeup\n"); - return -EINVAL; - } - return 0; }
@@ -2451,7 +2427,7 @@ static int dwc3_gadget_wakeup(struct usb_gadget *g) spin_unlock_irqrestore(&dwc->lock, flags); return -EINVAL; } - ret = __dwc3_gadget_wakeup(dwc, true); + ret = __dwc3_gadget_wakeup(dwc);
spin_unlock_irqrestore(&dwc->lock, flags);
@@ -2479,14 +2455,10 @@ static int dwc3_gadget_func_wakeup(struct usb_gadget *g, int intf_id) */ link_state = dwc3_gadget_get_link_state(dwc); if (link_state == DWC3_LINK_STATE_U3) { - ret = __dwc3_gadget_wakeup(dwc, false); - if (ret) { - spin_unlock_irqrestore(&dwc->lock, flags); - return -EINVAL; - } - dwc3_resume_gadget(dwc); - dwc->suspended = false; - dwc->link_state = DWC3_LINK_STATE_U0; + dwc->wakeup_pending_funcs |= BIT(intf_id); + ret = __dwc3_gadget_wakeup(dwc); + spin_unlock_irqrestore(&dwc->lock, flags); + return ret; }
ret = dwc3_send_gadget_generic_command(dwc, DWC3_DGCMD_DEV_NOTIFICATION, @@ -4353,6 +4325,8 @@ static void dwc3_gadget_linksts_change_interrupt(struct dwc3 *dwc, { enum dwc3_link_state next = evtinfo & DWC3_LINK_STATE_MASK; unsigned int pwropt; + int ret; + int intf_id;
/* * WORKAROUND: DWC3 < 2.50a have an issue when configured without @@ -4428,7 +4402,7 @@ static void dwc3_gadget_linksts_change_interrupt(struct dwc3 *dwc,
switch (next) { case DWC3_LINK_STATE_U0: - if (dwc->gadget->wakeup_armed) { + if (dwc->gadget->wakeup_armed || dwc->wakeup_pending_funcs) { dwc3_gadget_enable_linksts_evts(dwc, false); dwc3_resume_gadget(dwc); dwc->suspended = false; @@ -4451,6 +4425,18 @@ static void dwc3_gadget_linksts_change_interrupt(struct dwc3 *dwc, }
dwc->link_state = next; + + /* Proceed with func wakeup if any interfaces that has requested */ + while (dwc->wakeup_pending_funcs && (next == DWC3_LINK_STATE_U0)) { + intf_id = ffs(dwc->wakeup_pending_funcs) - 1; + ret = dwc3_send_gadget_generic_command(dwc, DWC3_DGCMD_DEV_NOTIFICATION, + DWC3_DGCMDPAR_DN_FUNC_WAKE | + DWC3_DGCMDPAR_INTF_SEL(intf_id)); + if (ret) + dev_err(dwc->dev, "Failed to send DN wake for intf %d\n", intf_id); + + dwc->wakeup_pending_funcs &= ~BIT(intf_id); + } }
static void dwc3_gadget_suspend_interrupt(struct dwc3 *dwc,