read from DAOS_NVME_POWER_MGMT env

Signed-off-by: Tom Nabarro <[email protected]>

Author: tanabarr

src/bio/bio_device.c

@@ -1080,7 +1080,7 @@ set_power_mgmt_completion(struct spdk_bdev_io *bdev_io, bool success, void *cb_a
 		D_ERROR("Set power management failed for device %s, NVMe status code/type: %d/%d\n",
 			d_bdev->bb_name, sc, sct);
 	} else {
-		D_INFO("Power management set to 0x1 for device %s\n", d_bdev->bb_name);
+		D_INFO("Power management value set on device %s\n", d_bdev->bb_name);
 	}
 
 	spdk_bdev_free_io(bdev_io);
@@ -1091,12 +1091,23 @@ bio_set_power_mgmt(struct bio_bdev *d_bdev, struct spdk_io_channel *channel)
 {
 	struct spdk_bdev    *bdev;
 	struct spdk_nvme_cmd cmd;
+	uint32_t             pwr_val = UINT32_MAX;
 	int                  rc;
 
 	D_ASSERT(d_bdev != NULL);
 	D_ASSERT(d_bdev->bb_desc != NULL);
 	D_ASSERT(channel != NULL);
 
+	rc = d_getenv_uint("DAOS_NVME_POWER_MGMT", &pwr_val);
+	if (rc == -DER_NONEXIST) {
+		return 0;
+	} else if (rc != 0) {
+		D_ERROR("DAOS_NVME_POWER_MGMT env value invalid, skipping set power management\n");
+		return -DER_INVAL;
+	}
+
+	D_INFO("New NVMe power management setting is %u\n", pwr_val);
+
 	bdev = spdk_bdev_desc_get_bdev(d_bdev->bb_desc);
 	if (bdev == NULL) {
 		D_ERROR("No bdev associated with device descriptor\n");
@@ -1117,7 +1128,7 @@ bio_set_power_mgmt(struct bio_bdev *d_bdev, struct spdk_io_channel *channel)
 	memset(&cmd, 0, sizeof(cmd));
 	cmd.opc   = SPDK_NVME_OPC_SET_FEATURES;
 	cmd.cdw10 = SPDK_NVME_FEAT_POWER_MANAGEMENT;
-	cmd.cdw11 = 0x1;
+	cmd.cdw11 = pwr_val;
 
 	rc = spdk_bdev_nvme_admin_passthru(d_bdev->bb_desc, channel, &cmd, NULL, 0,
 					   set_power_mgmt_completion, d_bdev);