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Message-Id: <20230814185043.9252-4-quic_eserrao@quicinc.com>
Date: Mon, 14 Aug 2023 11:50:43 -0700
From: Elson Roy Serrao <quic_eserrao@...cinc.com>
To: gregkh@...uxfoundation.org, Thinh.Nguyen@...opsys.com,
rogerq@...nel.org, robh+dt@...nel.org,
krzysztof.kozlowski+dt@...aro.org, conor+dt@...nel.org,
devicetree@...r.kernel.org
Cc: linux-kernel@...r.kernel.org, linux-usb@...r.kernel.org,
Elson Roy Serrao <quic_eserrao@...cinc.com>
Subject: [PATCH v4 3/3] usb: dwc3: Modify runtime pm ops to handle bus suspend
The current implementation blocks the runtime pm operations when cable
is connected. This would block dwc3 to enter a low power state during
bus suspend scenario. Modify the runtime pm ops to handle bus suspend
case for such platforms where the controller low power mode entry/exit
is handled by the glue driver. This enablement is controlled through a
dt property and platforms capable of detecting bus resume can benefit
from this feature. Also modify the remote wakeup operations to trigger
runtime resume before sending wakeup signal.
Signed-off-by: Elson Roy Serrao <quic_eserrao@...cinc.com>
---
drivers/usb/dwc3/core.c | 28 ++++++++++++++++++++++++++--
drivers/usb/dwc3/core.h | 3 +++
drivers/usb/dwc3/gadget.c | 32 +++++++++++++++++++++++++-------
3 files changed, 54 insertions(+), 9 deletions(-)
diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 9c6bf054f15d..9bfd9bb18caf 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -1518,6 +1518,9 @@ static void dwc3_get_properties(struct dwc3 *dwc)
dwc->dis_split_quirk = device_property_read_bool(dev,
"snps,dis-split-quirk");
+ dwc->runtime_suspend_on_usb_suspend = device_property_read_bool(dev,
+ "snps,runtime-suspend-on-usb-suspend");
+
dwc->lpm_nyet_threshold = lpm_nyet_threshold;
dwc->tx_de_emphasis = tx_de_emphasis;
@@ -2029,6 +2032,9 @@ static int dwc3_resume_common(struct dwc3 *dwc, pm_message_t msg)
switch (dwc->current_dr_role) {
case DWC3_GCTL_PRTCAP_DEVICE:
+ /* runtime resume on bus resume scenario */
+ if (PMSG_IS_AUTO(msg) && dwc->connected)
+ break;
ret = dwc3_core_init_for_resume(dwc);
if (ret)
return ret;
@@ -2090,8 +2096,13 @@ static int dwc3_runtime_checks(struct dwc3 *dwc)
{
switch (dwc->current_dr_role) {
case DWC3_GCTL_PRTCAP_DEVICE:
- if (dwc->connected)
+ if (dwc->connected) {
+ /* bus suspend scenario */
+ if (dwc->runtime_suspend_on_usb_suspend &&
+ dwc->suspended)
+ break;
return -EBUSY;
+ }
break;
case DWC3_GCTL_PRTCAP_HOST:
default:
@@ -2107,9 +2118,22 @@ static int dwc3_runtime_suspend(struct device *dev)
struct dwc3 *dwc = dev_get_drvdata(dev);
int ret;
- if (dwc3_runtime_checks(dwc))
+ ret = dwc3_runtime_checks(dwc);
+ if (ret)
return -EBUSY;
+ switch (dwc->current_dr_role) {
+ case DWC3_GCTL_PRTCAP_DEVICE:
+ /* bus suspend case */
+ if (!ret && dwc->connected)
+ return 0;
+ break;
+ case DWC3_GCTL_PRTCAP_HOST:
+ default:
+ /* do nothing */
+ break;
+ }
+
ret = dwc3_suspend_common(dwc, PMSG_AUTO_SUSPEND);
if (ret)
return ret;
diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index a69ac67d89fe..f2f788a6b4b5 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -1124,6 +1124,8 @@ struct dwc3_scratchpad_array {
* @num_ep_resized: carries the current number endpoints which have had its tx
* fifo resized.
* @debug_root: root debugfs directory for this device to put its files in.
+ * @runtime_suspend_on_usb_suspend: true if dwc3 runtime suspend is allowed
+ * during bus suspend scenario.
*/
struct dwc3 {
struct work_struct drd_work;
@@ -1340,6 +1342,7 @@ struct dwc3 {
int last_fifo_depth;
int num_ep_resized;
struct dentry *debug_root;
+ bool runtime_suspend_on_usb_suspend;
};
#define INCRX_BURST_MODE 0
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 5fd067151fbf..978ce0e91164 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -2401,15 +2401,21 @@ static int dwc3_gadget_wakeup(struct usb_gadget *g)
return -EINVAL;
}
- spin_lock_irqsave(&dwc->lock, flags);
if (!dwc->gadget->wakeup_armed) {
dev_err(dwc->dev, "not armed for remote wakeup\n");
- spin_unlock_irqrestore(&dwc->lock, flags);
return -EINVAL;
}
- ret = __dwc3_gadget_wakeup(dwc, true);
+ ret = pm_runtime_resume_and_get(dwc->dev);
+ if (ret < 0) {
+ pm_runtime_set_suspended(dwc->dev);
+ return ret;
+ }
+
+ spin_lock_irqsave(&dwc->lock, flags);
+ ret = __dwc3_gadget_wakeup(dwc, true);
spin_unlock_irqrestore(&dwc->lock, flags);
+ pm_runtime_put_noidle(dwc->dev);
return ret;
}
@@ -2428,6 +2434,12 @@ static int dwc3_gadget_func_wakeup(struct usb_gadget *g, int intf_id)
return -EINVAL;
}
+ ret = pm_runtime_resume_and_get(dwc->dev);
+ if (ret < 0) {
+ pm_runtime_set_suspended(dwc->dev);
+ return ret;
+ }
+
spin_lock_irqsave(&dwc->lock, flags);
/*
* If the link is in U3, signal for remote wakeup and wait for the
@@ -2438,6 +2450,7 @@ static int dwc3_gadget_func_wakeup(struct usb_gadget *g, int intf_id)
ret = __dwc3_gadget_wakeup(dwc, false);
if (ret) {
spin_unlock_irqrestore(&dwc->lock, flags);
+ pm_runtime_put_noidle(dwc->dev);
return -EINVAL;
}
dwc3_resume_gadget(dwc);
@@ -2452,6 +2465,7 @@ static int dwc3_gadget_func_wakeup(struct usb_gadget *g, int intf_id)
dev_err(dwc->dev, "function remote wakeup failed, ret:%d\n", ret);
spin_unlock_irqrestore(&dwc->lock, flags);
+ pm_runtime_put_noidle(dwc->dev);
return ret;
}
@@ -2732,21 +2746,23 @@ static int dwc3_gadget_pullup(struct usb_gadget *g, int is_on)
/*
* Avoid issuing a runtime resume if the device is already in the
* suspended state during gadget disconnect. DWC3 gadget was already
- * halted/stopped during runtime suspend.
+ * halted/stopped during runtime suspend except for bus suspend case
+ * where we would have skipped the controller halt.
*/
if (!is_on) {
pm_runtime_barrier(dwc->dev);
- if (pm_runtime_suspended(dwc->dev))
+ if (pm_runtime_suspended(dwc->dev) && !dwc->connected)
return 0;
}
/*
* Check the return value for successful resume, or error. For a
* successful resume, the DWC3 runtime PM resume routine will handle
- * the run stop sequence, so avoid duplicate operations here.
+ * the run stop sequence except for bus resume case, so avoid
+ * duplicate operations here.
*/
ret = pm_runtime_get_sync(dwc->dev);
- if (!ret || ret < 0) {
+ if ((!ret && !dwc->connected) || ret < 0) {
pm_runtime_put(dwc->dev);
if (ret < 0)
pm_runtime_set_suspended(dwc->dev);
@@ -4331,6 +4347,8 @@ static void dwc3_gadget_suspend_interrupt(struct dwc3 *dwc,
}
dwc->link_state = next;
+ pm_runtime_mark_last_busy(dwc->dev);
+ pm_request_autosuspend(dwc->dev);
}
static void dwc3_gadget_interrupt(struct dwc3 *dwc,
--
2.17.1
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