[PATCH] 6pack persistence fix
Fix the p-persistence CSMA algorithm which in simplex mode was starting
with a slottime delay before doing anything else as if there was carrier
collision resulting in bad performance on simplex links.
Signed-off-by: Ralf Baechle DL5RB <ralf@linux-mips.org>
Acked-by: Jeff Garzik <jgarzik@pobox.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/net/hamradio/6pack.c b/drivers/net/hamradio/6pack.c
index e44f8e9..f9e3be9 100644
--- a/drivers/net/hamradio/6pack.c
+++ b/drivers/net/hamradio/6pack.c
@@ -130,12 +130,11 @@
#define AX25_6PACK_HEADER_LEN 0
-static void sp_start_tx_timer(struct sixpack *);
static void sixpack_decode(struct sixpack *, unsigned char[], int);
static int encode_sixpack(unsigned char *, unsigned char *, int, unsigned char);
/*
- * perform the persistence/slottime algorithm for CSMA access. If the
+ * Perform the persistence/slottime algorithm for CSMA access. If the
* persistence check was successful, write the data to the serial driver.
* Note that in case of DAMA operation, the data is not sent here.
*/
@@ -143,7 +142,7 @@
static void sp_xmit_on_air(unsigned long channel)
{
struct sixpack *sp = (struct sixpack *) channel;
- int actual;
+ int actual, when = sp->slottime;
static unsigned char random;
random = random * 17 + 41;
@@ -159,20 +158,10 @@
sp->tty->driver->write(sp->tty, &sp->led_state, 1);
sp->status2 = 0;
} else
- sp_start_tx_timer(sp);
+ mod_timer(&sp->tx_t, jiffies + ((when + 1) * HZ) / 100);
}
/* ----> 6pack timer interrupt handler and friends. <---- */
-static void sp_start_tx_timer(struct sixpack *sp)
-{
- int when = sp->slottime;
-
- del_timer(&sp->tx_t);
- sp->tx_t.data = (unsigned long) sp;
- sp->tx_t.function = sp_xmit_on_air;
- sp->tx_t.expires = jiffies + ((when + 1) * HZ) / 100;
- add_timer(&sp->tx_t);
-}
/* Encapsulate one AX.25 frame and stuff into a TTY queue. */
static void sp_encaps(struct sixpack *sp, unsigned char *icp, int len)
@@ -243,8 +232,7 @@
sp->xleft = count;
sp->xhead = sp->xbuff;
sp->status2 = count;
- if (sp->duplex == 0)
- sp_start_tx_timer(sp);
+ sp_xmit_on_air((unsigned long)sp);
}
return;