[SCSI] cxgb3i: Outgoing pdus need to observe skb's MAX_SKB_FRAGS

Need to make sure the outgoing pdu can fit into a single skb.  When
calulating the max. outgoing pdu payload size, take into consideration
of
- data can be held in the skb's fragment list, assume 512 bytes per
  fragment, and
- data can be held in the headroom.

Signed-off-by: Karen Xie <kxie@chelsio.com>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

1 files changed, 6 insertions, 11 deletions

diff --git a/drivers/scsi/cxgb3i/cxgb3i_iscsi.c b/drivers/scsi/cxgb3i/cxgb3i_iscsi.c
index f0434b74554c..fa2a44f37b36 100644
--- a/drivers/scsi/cxgb3i/cxgb3i_iscsi.c
+++ b/drivers/scsi/cxgb3i/cxgb3i_iscsi.c
@@ -403,17 +403,15 @@ static inline int cxgb3i_conn_max_xmit_dlength(struct iscsi_conn *conn)
 {
         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
         struct cxgb3i_conn *cconn = tcp_conn->dd_data;
-        unsigned int max = min_t(unsigned int, ULP2_MAX_PDU_PAYLOAD,
-                                 cconn->hba->snic->tx_max_size -
-                                 ISCSI_PDU_NONPAYLOAD_MAX);
+        unsigned int max = max(512 * MAX_SKB_FRAGS, SKB_TX_HEADROOM);
 
+        max = min(cconn->hba->snic->tx_max_size, max);
         if (conn->max_xmit_dlength)
-                conn->max_xmit_dlength = min_t(unsigned int,
-                                                conn->max_xmit_dlength, max);
+                conn->max_xmit_dlength = min(conn->max_xmit_dlength, max);
         else
                 conn->max_xmit_dlength = max;
         align_pdu_size(conn->max_xmit_dlength);
-        cxgb3i_log_info("conn 0x%p, max xmit %u.\n",
+        cxgb3i_api_debug("conn 0x%p, max xmit %u.\n",
                          conn, conn->max_xmit_dlength);
         return 0;
 }
@@ -428,9 +426,7 @@ static inline int cxgb3i_conn_max_recv_dlength(struct iscsi_conn *conn)
 {
         struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
         struct cxgb3i_conn *cconn = tcp_conn->dd_data;
-        unsigned int max = min_t(unsigned int, ULP2_MAX_PDU_PAYLOAD,
-                                 cconn->hba->snic->rx_max_size -
-                                 ISCSI_PDU_NONPAYLOAD_MAX);
+        unsigned int max = cconn->hba->snic->rx_max_size;
 
         align_pdu_size(max);
         if (conn->max_recv_dlength) {
@@ -440,8 +436,7 @@ static inline int cxgb3i_conn_max_recv_dlength(struct iscsi_conn *conn)
                                          conn->max_recv_dlength, max);
                         return -EINVAL;
                 }
-                conn->max_recv_dlength = min_t(unsigned int,
-                                                conn->max_recv_dlength, max);
+                conn->max_recv_dlength = min(conn->max_recv_dlength, max);
                 align_pdu_size(conn->max_recv_dlength);
         } else
                 conn->max_recv_dlength = max;