[dpdk-stable] [PATCH v2] bus/ifpga: fix ifpga afu driver probe failure handler

[Ferruh Yigit <ferruh.yigit@intel.com>]

From: Andy Pei <andy.pei@intel.com>

In the original code, when an AFU device probe a driver,
if the first driver in the driver list does not support
this device or some error happens, bus probe returns an error.

With this patch, a device will try to match driver in the driver
list one by one until an appropriate driver is found.

If some error happens, the error is returned. If the current driver
does not support the device, just try the next driver in the list.

If all the drivers in the list are tried and no driver matches,
0 is returned. Otherwise, the error code is returned.

Fixes: 05fa3d4a6539 ("bus/ifpga: add Intel FPGA bus library")
Cc: stable@dpdk.org

Signed-off-by: Andy Pei <andy.pei@intel.com>
Reviewed-by: Ferruh Yigit <ferruh.yigit@intel.com>
Acked-by: Rosen Xu <rosen.xu@intel.com>
---
 drivers/bus/ifpga/ifpga_bus.c | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/drivers/bus/ifpga/ifpga_bus.c b/drivers/bus/ifpga/ifpga_bus.c
index e4b7b6f50..55d3abf9f 100644
--- a/drivers/bus/ifpga/ifpga_bus.c
+++ b/drivers/bus/ifpga/ifpga_bus.c
@@ -306,12 +306,19 @@ ifpga_probe_all_drivers(struct rte_afu_device *afu_dev)
 	}
 
 	TAILQ_FOREACH(drv, &ifpga_afu_drv_list, next) {
-		if (ifpga_probe_one_driver(drv, afu_dev)) {
-			ret = -1;
-			break;
-		}
+		ret = ifpga_probe_one_driver(drv, afu_dev);
+		if (ret < 0)
+			/* negative value is an error */
+			return ret;
+		if (ret > 0)
+			/* positive value means driver doesn't support it */
+			continue;
+		return 0;
 	}
-	return ret;
+	if ((ret > 0) && (afu_dev->driver == NULL))
+		return 0;
+	else
+		return ret;
 }
 
 /*
-- 
2.17.2