can bcm: fix tx_setup off-by-one errors

This patch fixes two off-by-one errors that canceled each other out.
Checking for the same condition two times in bcm_tx_timeout_tsklet() reduced
the count of frames to be sent by one. This did not show up the first time
tx_setup is invoked as an additional frame is sent due to TX_ANNONCE.
Invoking a second tx_setup on the same item led to a reduced (by 1) number of
sent frames.

Reported-by: Andre Naujoks <nautsch@gmail.com>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Upstream commit https://github.com/davem330/net/commit/aabdcb0b553b9c9547b1a506b34d55a764745870

git-svn-id: svn://svn.berlios.de//socketcan/trunk@1274 030b6a49-0b11-0410-94ab-b0dab22257f2

diff --git a/kernel/2.6/net/can/bcm-prior-2-6-22.c b/kernel/2.6/net/can/bcm-prior-2-6-22.c
index 10b200838dc3df4bd70cb24f6471ef3b14fbf0c6..1254675b1729ab82ed3e6c969277e41ddf9219f4 100644 (file)
--- a/kernel/2.6/net/can/bcm-prior-2-6-22.c
+++ b/kernel/2.6/net/can/bcm-prior-2-6-22.c
@@ -416,9 +416,6 @@ static void bcm_tx_timeout_handler(unsigned long data)
 
                        bcm_send_to_user(op, &msg_head, NULL, 0);
                }
-       }
-
-       if (op->j_ival1 && (op->count > 0)) {
 
                /* send (next) frame */
                bcm_can_tx(op);
@@ -958,15 +955,19 @@ static int bcm_tx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
                /* spec: send can_frame when starting timer */
                op->flags |= TX_ANNOUNCE;
 
-               if (op->j_ival1 && (op->count > 0)) {
+               /* only start timer when having more frames than sent below */
+               if (op->j_ival1 && (op->count > 1)) {
                        /* op->count-- is done in bcm_tx_timeout_handler */
                        mod_timer(&op->timer, jiffies + op->j_ival1);
                } else
                        mod_timer(&op->timer, jiffies + op->j_ival2);
        }
 
-       if (op->flags & TX_ANNOUNCE)
+       if (op->flags & TX_ANNOUNCE) {
                bcm_can_tx(op);
+               if (op->j_ival1 && (op->count > 0))
+                       op->count--;
+       }
 
        return msg_head->nframes * CFSIZ + MHSIZ;
 }

diff --git a/kernel/2.6/net/can/bcm.c b/kernel/2.6/net/can/bcm.c
index 11c527953685126979ef3d6276256eef59d2a5d8..96333982589d2cc11f2642b022d1b0da2b2f301c 100644 (file)
--- a/kernel/2.6/net/can/bcm.c
+++ b/kernel/2.6/net/can/bcm.c
@@ -481,9 +481,6 @@ static void bcm_tx_timeout_tsklet(unsigned long data)
 
                        bcm_send_to_user(op, &msg_head, NULL, 0);
                }
-       }
-
-       if (op->kt_ival1.tv64 && (op->count > 0)) {
 
                /* send (next) frame */
                bcm_can_tx(op);
@@ -1101,8 +1098,9 @@ static int bcm_tx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
                /* spec: send can_frame when starting timer */
                op->flags |= TX_ANNOUNCE;
 
-               if (op->kt_ival1.tv64 && (op->count > 0)) {
-                       /* op->count-- is done in bcm_tx_timeout_handler */
+               /* only start timer when having more frames than sent below */
+               if (op->kt_ival1.tv64 && (op->count > 1)) {
+                       /* op->count-- is done in bcm_tx_timeout_tsklet */
                        hrtimer_start(&op->timer, op->kt_ival1,
                                      HRTIMER_MODE_REL);
                } else
@@ -1110,8 +1108,11 @@ static int bcm_tx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
                                      HRTIMER_MODE_REL);
        }
 
-       if (op->flags & TX_ANNOUNCE)
+       if (op->flags & TX_ANNOUNCE) {
                bcm_can_tx(op);
+               if (op->kt_ival1.tv64 && (op->count > 0))
+                       op->count--;
+       }
 
        return msg_head->nframes * CFSIZ + MHSIZ;
 }