[PATCH] rtnet: Fix lifecycle management of mapped rtskbs

[Jan Kiszka via Xenomai]

Do not add rtskbs to the rtskb_list which are not mappend because
rtdev_unmap_rtskb will not remove such rtskbs again (buf_dma_addr ==
RTSKB_UNMAPPED). In fact, rtskb_list should be called rtskb_mapped_list,
so refactor this while at it.

Signed-off-by: Jan Kiszka <jan.kis...@siemens.com>
---
 kernel/drivers/net/stack/rtdev.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/kernel/drivers/net/stack/rtdev.c b/kernel/drivers/net/stack/rtdev.c
index 5eb73ce1a4..7b267f2a7c 100644
--- a/kernel/drivers/net/stack/rtdev.c
+++ b/kernel/drivers/net/stack/rtdev.c
@@ -44,9 +44,9 @@ MODULE_PARM_DESC(device_rtskbs, "Number of additional global 
realtime socket "
 struct rtnet_device         *rtnet_devices[MAX_RT_DEVICES];
 static struct rtnet_device  *loopback_device;
 static DEFINE_RTDM_LOCK(rtnet_devices_rt_lock);
+static LIST_HEAD(rtskb_mapped_list);
 
 LIST_HEAD(event_hook_list);
-LIST_HEAD(rtskb_list);
 DEFINE_MUTEX(rtnet_devices_nrt_lock);
 
 static int rtdev_locked_xmit(struct rtskb *skb, struct rtnet_device *rtdev);
@@ -412,8 +412,8 @@ int rtdev_map_rtskb(struct rtskb *skb)
        }
     }
 
-    if (!err)
-       list_add(&skb->entry, &rtskb_list);
+    if (!err && skb->buf_dma_addr != RTSKB_UNMAPPED)
+       list_add(&skb->entry, &rtskb_mapped_list);
 
     mutex_unlock(&rtnet_devices_nrt_lock);
 
@@ -430,7 +430,7 @@ static int rtdev_map_all_rtskbs(struct rtnet_device *rtdev)
     if (!rtdev->map_rtskb)
        return 0;
 
-    list_for_each_entry(skb, &rtskb_list, entry) {
+    list_for_each_entry(skb, &rtskb_mapped_list, entry) {
        err = rtskb_map(rtdev, skb);
        if (err)
           break;
@@ -474,7 +474,7 @@ static void rtdev_unmap_all_rtskbs(struct rtnet_device 
*rtdev)
     if (!rtdev->unmap_rtskb)
        return;
 
-    list_for_each_entry(skb, &rtskb_list, entry) {
+    list_for_each_entry(skb, &rtskb_mapped_list, entry) {
        rtdev->unmap_rtskb(rtdev, skb);
     }
 }
-- 
2.16.4