[dpdk-dev] [PATCH v2] eal: fix positive error codes from probe/remove

[Ilya Maximets <i.maximets@samsung.com>]

According to API, 'rte_dev_probe()' and 'rte_dev_remove()' must
return 0 or negative error code. Bus code returns positive values
if device wasn't recognized by any driver, so the result of
'bus->plug/unplug()' must be converted. 'local_dev_probe()' and
'local_dev_remove()' also has their internal API, so the conversion
should be done there.

Positive on remove means that device not found by driver.
Positive on probe means that there are no suitable buses/drivers,
i.e. device is not supported.

Users of these API fixed to provide a good example by respecting
DPDK API. This also will allow to catch such issues in the future.

CC: stable@dpdk.org
Fixes: a3ee360f4440 ("eal: add hotplug add/remove device")
Fixes: 244d5130719c ("eal: enable hotplug on multi-process")

Signed-off-by: Ilya Maximets <i.maximets@samsung.com>
---

Version 2:

    * Fixed API callers.
    * Check for probe moved from 'rte_dev_probe' to 'local_dev_probe'.

 app/test-pmd/testpmd.c                 | 4 ++--
 drivers/net/failsafe/failsafe.c        | 2 +-
 drivers/net/failsafe/failsafe_eal.c    | 4 ++--
 drivers/net/failsafe/failsafe_ether.c  | 2 +-
 drivers/net/vdev_netvsc/vdev_netvsc.c  | 2 +-
 lib/librte_eal/common/eal_common_dev.c | 5 ++++-
 6 files changed, 11 insertions(+), 8 deletions(-)

diff --git a/app/test-pmd/testpmd.c b/app/test-pmd/testpmd.c
index 4f2a431e4..52244b442 100644
--- a/app/test-pmd/testpmd.c
+++ b/app/test-pmd/testpmd.c
@@ -2361,7 +2361,7 @@ attach_port(char *identifier)
 		return;
 	}
 
-	if (rte_dev_probe(identifier) != 0) {
+	if (rte_dev_probe(identifier) < 0) {
 		TESTPMD_LOG(ERR, "Failed to attach port %s\n", identifier);
 		return;
 	}
@@ -2431,7 +2431,7 @@ detach_port_device(portid_t port_id)
 			port_flow_flush(port_id);
 	}
 
-	if (rte_dev_remove(dev) != 0) {
+	if (rte_dev_remove(dev) < 0) {
 		TESTPMD_LOG(ERR, "Failed to detach device %s\n", dev->name);
 		return;
 	}
diff --git a/drivers/net/failsafe/failsafe.c b/drivers/net/failsafe/failsafe.c
index e91c274d8..19dd71d4e 100644
--- a/drivers/net/failsafe/failsafe.c
+++ b/drivers/net/failsafe/failsafe.c
@@ -374,7 +374,7 @@ rte_pmd_failsafe_probe(struct rte_vdev_device *vdev)
 			}
 			if (!devargs_already_listed(&devargs)) {
 				ret = rte_dev_probe(devargs.name);
-				if (ret != 0) {
+				if (ret < 0) {
 					ERROR("Failed to probe devargs %s",
 					      devargs.name);
 					continue;
diff --git a/drivers/net/failsafe/failsafe_eal.c b/drivers/net/failsafe/failsafe_eal.c
index 820a915f7..b9fc50867 100644
--- a/drivers/net/failsafe/failsafe_eal.c
+++ b/drivers/net/failsafe/failsafe_eal.c
@@ -48,7 +48,7 @@ fs_bus_init(struct rte_eth_dev *dev)
 			ret = rte_eal_hotplug_add(da->bus->name,
 						  da->name,
 						  da->args);
-			if (ret) {
+			if (ret < 0) {
 				ERROR("sub_device %d probe failed %s%s%s", i,
 				      rte_errno ? "(" : "",
 				      rte_errno ? strerror(rte_errno) : "",
@@ -147,7 +147,7 @@ fs_bus_uninit(struct rte_eth_dev *dev)
 
 	FOREACH_SUBDEV_STATE(sdev, i, dev, DEV_PROBED) {
 		sdev_ret = rte_dev_remove(sdev->dev);
-		if (sdev_ret) {
+		if (sdev_ret < 0) {
 			ERROR("Failed to remove requested device %s (err: %d)",
 			      sdev->dev->name, sdev_ret);
 			continue;
diff --git a/drivers/net/failsafe/failsafe_ether.c b/drivers/net/failsafe/failsafe_ether.c
index 4746fad36..504c76edb 100644
--- a/drivers/net/failsafe/failsafe_ether.c
+++ b/drivers/net/failsafe/failsafe_ether.c
@@ -284,7 +284,7 @@ fs_dev_remove(struct sub_device *sdev)
 		/* fallthrough */
 	case DEV_PROBED:
 		ret = rte_dev_remove(sdev->dev);
-		if (ret) {
+		if (ret < 0) {
 			ERROR("Bus detach failed for sub_device %u",
 			      SUB_ID(sdev));
 		} else {
diff --git a/drivers/net/vdev_netvsc/vdev_netvsc.c b/drivers/net/vdev_netvsc/vdev_netvsc.c
index edab63e3a..1fcf90d7b 100644
--- a/drivers/net/vdev_netvsc/vdev_netvsc.c
+++ b/drivers/net/vdev_netvsc/vdev_netvsc.c
@@ -633,7 +633,7 @@ vdev_netvsc_netvsc_probe(const struct if_nameindex *iface,
 		ctx->devname, ctx->devargs);
 	vdev_netvsc_foreach_iface(vdev_netvsc_device_probe, 0, ctx);
 	ret = rte_eal_hotplug_add("vdev", ctx->devname, ctx->devargs);
-	if (ret)
+	if (ret < 0)
 		goto error;
 	LIST_INSERT_HEAD(&vdev_netvsc_ctx_list, ctx, entry);
 	++vdev_netvsc_ctx_count;
diff --git a/lib/librte_eal/common/eal_common_dev.c b/lib/librte_eal/common/eal_common_dev.c
index 824b8f926..f8f2a94b3 100644
--- a/lib/librte_eal/common/eal_common_dev.c
+++ b/lib/librte_eal/common/eal_common_dev.c
@@ -172,6 +172,9 @@ local_dev_probe(const char *devargs, struct rte_device **new_dev)
 	 */
 
 	ret = dev->bus->plug(dev);
+	if (ret > 0)
+		ret = -ENOTSUP;
+
 	if (ret && !rte_dev_is_probed(dev)) { /* if hasn't ever succeeded */
 		RTE_LOG(ERR, EAL, "Driver cannot attach the device (%s)\n",
 			dev->name);
@@ -319,7 +322,7 @@ local_dev_remove(struct rte_device *dev)
 	if (ret) {
 		RTE_LOG(ERR, EAL, "Driver cannot detach the device (%s)\n",
 			dev->name);
-		return ret;
+		return (ret < 0) ? ret : -ENOENT;
 	}
 
 	return 0;
-- 
2.17.1