MHI devices may not be destroyed during suspend/hibernation, so need
to unprepare/prepare MHI channels throughout the transition, this is
done by adding suspend/resume callbacks.
The suspend callback is called in the late suspend stage, this means
MHI channels are still alive at suspend stage, and that makes it
possible for an MHI controller driver to communicate with others over
those channels at suspend stage. While the resume callback is called
in the early resume stage, for a similar reason.
Tested-on: WCN6855 hw2.0 PCI WLAN.HSP.1.1-03125-QCAHSPSWPL_V1_V2_SILICONZ_LITE-3.6510.30
Signed-off-by: Baochen Qiang <quic_bqiang@xxxxxxxxxxx>
---
net/qrtr/mhi.c | 27 +++++++++++++++++++++++++++
1 file changed, 27 insertions(+)
diff --git a/net/qrtr/mhi.c b/net/qrtr/mhi.c
index 9ced13c0627a..e96b82a6742c 100644
--- a/net/qrtr/mhi.c
+++ b/net/qrtr/mhi.c
@@ -118,6 +118,32 @@ static const struct mhi_device_id qcom_mhi_qrtr_id_table[] = {
};
MODULE_DEVICE_TABLE(mhi, qcom_mhi_qrtr_id_table);
+static int __maybe_unused qcom_mhi_qrtr_pm_suspend_late(struct device *dev)
+{
+ struct mhi_device *mhi_dev = container_of(dev, struct mhi_device, dev);
+
+ mhi_unprepare_from_transfer(mhi_dev);
+
+ return 0;
+}
+
+static int __maybe_unused qcom_mhi_qrtr_pm_resume_early(struct device *dev)
+{
+ struct mhi_device *mhi_dev = container_of(dev, struct mhi_device, dev);
+ int rc;
+
+ rc = mhi_prepare_for_transfer_autoqueue(mhi_dev);
+ if (rc)
+ dev_err(dev, "failed to prepare for autoqueue transfer %d\n", rc);
+
+ return rc;
+}
+
+static const struct dev_pm_ops qcom_mhi_qrtr_pm_ops = {
+ SET_LATE_SYSTEM_SLEEP_PM_OPS(qcom_mhi_qrtr_pm_suspend_late,
+ qcom_mhi_qrtr_pm_resume_early)
+};
+
static struct mhi_driver qcom_mhi_qrtr_driver = {
.probe = qcom_mhi_qrtr_probe,
.remove = qcom_mhi_qrtr_remove,
@@ -126,6 +152,7 @@ static struct mhi_driver qcom_mhi_qrtr_driver = {
.id_table = qcom_mhi_qrtr_id_table,
.driver = {
.name = "qcom_mhi_qrtr",
+ .pm = &qcom_mhi_qrtr_pm_ops,
},
};
--
2.25.1
