USB: Allow skipping device resume during system resume
Some buses would like to keep their devices in suspend state during system
resume. For example HSIC controller driver prevent system suspend when
HSIC device is active. If this device is resumed, during system resume
HSIC controller acquire wake lock and prevent the subsequent suspend till
HSIC device is auto suspended.
CRs-Fixed: 403975
Change-Id: I93ccd874bf489190e4afb94b533db47bb2911db8
Signed-off-by: Pavankumar Kondeti <pkondeti@codeaurora.org>
diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c
index 19e1244..a292416 100644
--- a/drivers/usb/core/driver.c
+++ b/drivers/usb/core/driver.c
@@ -1357,6 +1357,9 @@
{
struct usb_device *udev = to_usb_device(dev);
+ if (udev->bus->skip_resume && udev->state == USB_STATE_SUSPENDED)
+ return 0;
+
unbind_no_pm_drivers_interfaces(udev);
/* From now on we are sure all drivers support suspend/resume
@@ -1386,6 +1389,15 @@
struct usb_device *udev = to_usb_device(dev);
int status;
+ /*
+ * Some buses would like to keep their devices in suspend
+ * state after system resume. Their resume happen when
+ * a remote wakeup is detected or interface driver start
+ * I/O.
+ */
+ if (udev->bus->skip_resume)
+ return 0;
+
/* For all calls, take the device back to full power and
* tell the PM core in case it was autosuspended previously.
* Unbind the interfaces that will need rebinding later,
diff --git a/drivers/usb/host/ehci-msm-hsic.c b/drivers/usb/host/ehci-msm-hsic.c
index b7f1878..0a48a6e 100644
--- a/drivers/usb/host/ehci-msm-hsic.c
+++ b/drivers/usb/host/ehci-msm-hsic.c
@@ -1522,6 +1522,8 @@
return -ENOMEM;
}
+ hcd_to_bus(hcd)->skip_resume = true;
+
hcd->irq = platform_get_irq(pdev, 0);
if (hcd->irq < 0) {
dev_err(&pdev->dev, "Unable to get IRQ resource\n");
@@ -1791,6 +1793,15 @@
if (device_may_wakeup(dev))
disable_irq_wake(hcd->irq);
+ /*
+ * Keep HSIC in Low Power Mode if system is resumed
+ * by any other wakeup source. HSIC is resumed later
+ * when remote wakeup is received or interface driver
+ * start I/O.
+ */
+ if (!atomic_read(&mehci->pm_usage_cnt))
+ return 0;
+
ret = msm_hsic_resume(mehci);
if (ret)
return ret;
diff --git a/include/linux/usb.h b/include/linux/usb.h
index 68a87bf..44c64e8 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -368,6 +368,15 @@
struct mon_bus *mon_bus; /* non-null when associated */
int monitored; /* non-zero when monitored */
#endif
+ unsigned skip_resume:1; /* All USB devices are brought into full
+ * power state after system resume. It
+ * is desirable for some buses to keep
+ * their devices in suspend state even
+ * after system resume. The devices
+ * are resumed later when a remote
+ * wakeup is detected or an interface
+ * driver starts I/O.
+ */
};
/* ----------------------------------------------------------------------- */