[SCSI] cxgb3i: fix cpu use abuse during writes

When doing a lot (128) of large writes (256K) we can hit the cxgb3_snd_win
check pretty easily. The driver's xmit thread then takes 100% of the cpu.

The driver should not be returning -EAGAIN for this problem. It should
be returing -ENOBUFS, then when the window is opened again it should
queue the xmit thread (it already wakes the xmit thread).

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

1 files changed, 3 insertions, 1 deletions

diff --git a/drivers/scsi/cxgb3i/cxgb3i_offload.c b/drivers/scsi/cxgb3i/cxgb3i_offload.c
index 4d8654cdbdae..e11c9c180f39 100644
--- a/drivers/scsi/cxgb3i/cxgb3i_offload.c
+++ b/drivers/scsi/cxgb3i/cxgb3i_offload.c
@@ -1737,7 +1737,7 @@ int cxgb3i_c3cn_send_pdus(struct s3_conn *c3cn, struct sk_buff *skb)
                 c3cn_tx_debug("c3cn 0x%p, snd %u - %u > %u.\n",
                                 c3cn, c3cn->write_seq, c3cn->snd_una,
                                 cxgb3_snd_win);
-                err = -EAGAIN;
+                err = -ENOBUFS;
                 goto out_err;
         }
 
@@ -1775,6 +1775,8 @@ done:
 out_err:
         if (copied == 0 && err == -EPIPE)
                 copied = c3cn->err ? c3cn->err : -EPIPE;
+        else
+                copied = err;
         goto done;
 }