diff options
Diffstat (limited to 'drivers/char')
| -rw-r--r-- | drivers/char/synclink_gt.c | 72 |
1 files changed, 30 insertions, 42 deletions
diff --git a/drivers/char/synclink_gt.c b/drivers/char/synclink_gt.c index 1386625fc4c..a2e67e6df3a 100644 --- a/drivers/char/synclink_gt.c +++ b/drivers/char/synclink_gt.c @@ -467,7 +467,6 @@ static unsigned int free_tbuf_count(struct slgt_info *info); static unsigned int tbuf_bytes(struct slgt_info *info); static void reset_tbufs(struct slgt_info *info); static void tdma_reset(struct slgt_info *info); -static void tdma_start(struct slgt_info *info); static void tx_load(struct slgt_info *info, const char *buf, unsigned int count); static void get_signals(struct slgt_info *info); @@ -795,6 +794,18 @@ static void set_termios(struct tty_struct *tty, struct ktermios *old_termios) } } +static void update_tx_timer(struct slgt_info *info) +{ + /* + * use worst case speed of 1200bps to calculate transmit timeout + * based on data in buffers (tbuf_bytes) and FIFO (128 bytes) + */ + if (info->params.mode == MGSL_MODE_HDLC) { + int timeout = (tbuf_bytes(info) * 7) + 1000; + mod_timer(&info->tx_timer, jiffies + msecs_to_jiffies(timeout)); + } +} + static int write(struct tty_struct *tty, const unsigned char *buf, int count) { @@ -838,8 +849,18 @@ start: spin_lock_irqsave(&info->lock,flags); if (!info->tx_active) tx_start(info); - else - tdma_start(info); + else if (!(rd_reg32(info, TDCSR) & BIT0)) { + /* transmit still active but transmit DMA stopped */ + unsigned int i = info->tbuf_current; + if (!i) + i = info->tbuf_count; + i--; + /* if DMA buf unsent must try later after tx idle */ + if (desc_count(info->tbufs[i])) + ret = 0; + } + if (ret > 0) + update_tx_timer(info); spin_unlock_irqrestore(&info->lock,flags); } @@ -1502,10 +1523,9 @@ static int hdlcdev_xmit(struct sk_buff *skb, struct net_device *dev) /* save start time for transmit timeout detection */ dev->trans_start = jiffies; - /* start hardware transmitter if necessary */ spin_lock_irqsave(&info->lock,flags); - if (!info->tx_active) - tx_start(info); + tx_start(info); + update_tx_timer(info); spin_unlock_irqrestore(&info->lock,flags); return 0; @@ -3946,50 +3966,19 @@ static void tx_start(struct slgt_info *info) slgt_irq_on(info, IRQ_TXUNDER + IRQ_TXIDLE); /* clear tx idle and underrun status bits */ wr_reg16(info, SSR, (unsigned short)(IRQ_TXIDLE + IRQ_TXUNDER)); - if (info->params.mode == MGSL_MODE_HDLC) - mod_timer(&info->tx_timer, jiffies + - msecs_to_jiffies(5000)); } else { slgt_irq_off(info, IRQ_TXDATA); slgt_irq_on(info, IRQ_TXIDLE); /* clear tx idle status bit */ wr_reg16(info, SSR, IRQ_TXIDLE); } - tdma_start(info); + /* set 1st descriptor address and start DMA */ + wr_reg32(info, TDDAR, info->tbufs[info->tbuf_start].pdesc); + wr_reg32(info, TDCSR, BIT2 + BIT0); info->tx_active = true; } } -/* - * start transmit DMA if inactive and there are unsent buffers - */ -static void tdma_start(struct slgt_info *info) -{ - unsigned int i; - - if (rd_reg32(info, TDCSR) & BIT0) - return; - - /* transmit DMA inactive, check for unsent buffers */ - i = info->tbuf_start; - while (!desc_count(info->tbufs[i])) { - if (++i == info->tbuf_count) - i = 0; - if (i == info->tbuf_current) - return; - } - info->tbuf_start = i; - - /* there are unsent buffers, start transmit DMA */ - - /* reset needed if previous error condition */ - tdma_reset(info); - - /* set 1st descriptor address */ - wr_reg32(info, TDDAR, info->tbufs[info->tbuf_start].pdesc); - wr_reg32(info, TDCSR, BIT2 + BIT0); /* IRQ + DMA enable */ -} - static void tx_stop(struct slgt_info *info) { unsigned short val; @@ -5004,8 +4993,7 @@ static void tx_timeout(unsigned long context) info->icount.txtimeout++; } spin_lock_irqsave(&info->lock,flags); - info->tx_active = false; - info->tx_count = 0; + tx_stop(info); spin_unlock_irqrestore(&info->lock,flags); #if SYNCLINK_GENERIC_HDLC |