@@ -26,6 +26,7 @@
#include <linux/of_graph.h>
#include <linux/acpi.h>
#include <linux/pinctrl/consumer.h>
+#include <linux/pinctrl/devinfo.h>
#include <linux/reset.h>
#include <linux/bitfield.h>
@@ -2658,14 +2659,31 @@ static void dwc3_complete(struct device *dev)
dwc3_writel(dwc->regs, DWC3_GUCTL3, reg);
}
}
+
+static int dwc3_prepare(struct device *dev)
+{
+ struct dwc3 *dwc = dev_get_drvdata(dev);
+
+ /*
+ * Indicate to the PM core that it may safely leave the device in
+ * runtime suspend if runtime-suspended already in device mode.
+ */
+ if (dwc->current_dr_role == DWC3_GCTL_PRTCAP_DEVICE &&
+ pm_runtime_suspended(dev) &&
+ !dev_pinctrl(dev))
+ return 1;
+
+ return 0;
+}
#else
#define dwc3_complete NULL
+#define dwc3_prepare NULL
#endif /* CONFIG_PM_SLEEP */
static const struct dev_pm_ops dwc3_dev_pm_ops = {
SET_SYSTEM_SLEEP_PM_OPS(dwc3_suspend, dwc3_resume)
.complete = dwc3_complete,
-
+ .prepare = dwc3_prepare,
/*
* Runtime suspend halts the controller on disconnection. It relies on
* platforms with custom connection notification to start the controller
dwc3 device suspend/resume callbacks were being triggered during system suspend and resume even if the device was already runtime-suspended. This is redundant for device mode because the suspend and resume routines are essentially identical for system PM and runtime PM. To prevent these unnecessary callbacks, indicate to the PM core that it can safely leave the device in runtime suspend if it's already runtime-suspended in device mode by returning a positive value in prepare() callback. This optimization only applies to devices without pinctrl, as pinctrl has distinct logic tied to system suspend/resume. Signed-off-by: Roy Luo <royluo@google.com> --- Changes in v2: - leave the pinctrl logic untouched, apply the optimization only when pinctrl isn't being used. --- drivers/usb/dwc3/core.c | 20 +++++++++++++++++++- 1 file changed, 19 insertions(+), 1 deletion(-) base-commit: 0fed89a961ea851945d23cc35beb59d6e56c0964