[dpdk-dev] [PATCH] net/failsafe: do not probe device if plugged out

[Thomas Monjalon <thomas@monjalon.net>]

When probing a sub-devices which does not exist in the system,
some errors are logged:
	EAL: Cannot find unplugged device (0002:00:02.0)
	PMD: net_failsafe: ERROR: sub_device 0 probe failed

It is normal to have these errors when initializing the failsafe
device and its sub-devices.
But we do not need to log them at each probe.
And it is even less relevant if the sub-device has been plugged out.

The unavailable devices are skipped after the first probe, considering
two exceptions:
- The vdevs are always probed because they do not really exist on the
virtual bus before probing them.
- The sub-device list given by an executed command line may change
from one call to the next one, therefore it is considered to be always
the first one. Anyway, such external command should check the
device availability before passing it to the failsafe PMD.

Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
---
This patch is on top of the failsafe series which is
pending for integration in 17.08-rc2.
---
 drivers/net/failsafe/failsafe_eal.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/drivers/net/failsafe/failsafe_eal.c b/drivers/net/failsafe/failsafe_eal.c
index 3321dda71..5181066ed 100644
--- a/drivers/net/failsafe/failsafe_eal.c
+++ b/drivers/net/failsafe/failsafe_eal.c
@@ -49,6 +49,11 @@ fs_find_ethdev(const struct rte_device *dev)
 	return NULL;
 }
 
+static int cmp_dev_name(const struct rte_device *dev, const void *name)
+{
+	return strcmp(dev->name, name);
+}
+
 static int
 fs_bus_init(struct rte_eth_dev *dev)
 {
@@ -56,12 +61,24 @@ fs_bus_init(struct rte_eth_dev *dev)
 	struct rte_device *rdev;
 	struct rte_devargs *da;
 	uint8_t i;
+	static int first_init = 1;
 	int ret;
 
 	FOREACH_SUBDEV(sdev, i, dev) {
 		if (sdev->state != DEV_PARSED)
 			continue;
 		da = &sdev->devargs;
+
+		/* skip plugged out devices */
+		if (! first_init
+				&& sdev->cmdline == NULL
+				&& strcmp(da->bus->name, "vdev") != 0) {
+			da->bus->scan();
+			if (bus->find_device(NULL, cmp_dev_name, da->name) == NULL)
+				continue; /* device not found */
+		}
+
+		/* probe device */
 		rdev = rte_eal_hotplug_add(da->bus->name,
 					   da->name,
 					   da->args);
@@ -84,6 +101,10 @@ fs_bus_init(struct rte_eth_dev *dev)
 		ETH(sdev)->state = RTE_ETH_DEV_DEFERRED;
 		sdev->state = DEV_PROBED;
 	}
+
+	if (first_init)
+		first_init = 0;
+
 	return 0;
 }
 
-- 
2.13.2