[SUNGEM]: Fix NAPI assertion failure.

As reported by Johannes Berg:

I started getting this warning with recent kernels:

[  773.908927] ------------[ cut here ]------------
[  773.908954] Badness at net/core/dev.c:2204
 ...

If we loop more than once in gem_poll(), we'll
use more than the real budget in our gem_rx()
calls, thus eventually trigger the caller's
assertions in net_rx_action().

Subtract "work_done" from "budget" for the second
arg to gem_rx() to fix the bug.

Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/sungem.c b/drivers/net/sungem.c
index 9721279..4291458 100644 (file)
--- a/drivers/net/sungem.c
+++ b/drivers/net/sungem.c
@@ -912,7 +912,7 @@ static int gem_poll(struct napi_struct *napi, int budget)
                 * rx ring - must call napi_disable(), which
                 * schedule_timeout()'s if polling is already disabled.
                 */
-               work_done += gem_rx(gp, budget);
+               work_done += gem_rx(gp, budget - work_done);
 
                if (work_done >= budget)
                        return work_done;