diff options
Diffstat (limited to 'drivers/char')
| -rw-r--r-- | drivers/char/synclink_gt.c | 75 |
1 files changed, 46 insertions, 29 deletions
diff --git a/drivers/char/synclink_gt.c b/drivers/char/synclink_gt.c index 372a37e25620..bbb7f1292665 100644 --- a/drivers/char/synclink_gt.c +++ b/drivers/char/synclink_gt.c @@ -1,5 +1,5 @@ /* - * $Id: synclink_gt.c,v 4.36 2006/08/28 20:47:14 paulkf Exp $ + * $Id: synclink_gt.c,v 4.50 2007/07/25 19:29:25 paulkf Exp $ * * Device driver for Microgate SyncLink GT serial adapters. * @@ -93,7 +93,7 @@ * module identification */ static char *driver_name = "SyncLink GT"; -static char *driver_version = "$Revision: 4.36 $"; +static char *driver_version = "$Revision: 4.50 $"; static char *tty_driver_name = "synclink_gt"; static char *tty_dev_prefix = "ttySLG"; MODULE_LICENSE("GPL"); @@ -477,6 +477,7 @@ static void tx_set_idle(struct slgt_info *info); static unsigned int free_tbuf_count(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); @@ -904,6 +905,8 @@ start: spin_lock_irqsave(&info->lock,flags); if (!info->tx_active) tx_start(info); + else + tdma_start(info); spin_unlock_irqrestore(&info->lock,flags); } @@ -3871,44 +3874,58 @@ 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 (!(rd_reg32(info, TDCSR) & BIT0)) { - /* tx DMA stopped, restart tx DMA */ - tdma_reset(info); - /* set 1st descriptor address */ - wr_reg32(info, TDDAR, info->tbufs[info->tbuf_start].pdesc); - switch(info->params.mode) { - case MGSL_MODE_RAW: - case MGSL_MODE_MONOSYNC: - case MGSL_MODE_BISYNC: - wr_reg32(info, TDCSR, BIT2 + BIT0); /* IRQ + DMA enable */ - break; - default: - wr_reg32(info, TDCSR, BIT0); /* DMA enable */ - } - } - if (info->params.mode == MGSL_MODE_HDLC) mod_timer(&info->tx_timer, jiffies + msecs_to_jiffies(5000)); } else { - tdma_reset(info); - /* set 1st descriptor address */ - wr_reg32(info, TDDAR, info->tbufs[info->tbuf_start].pdesc); - slgt_irq_off(info, IRQ_TXDATA); slgt_irq_on(info, IRQ_TXIDLE); /* clear tx idle status bit */ wr_reg16(info, SSR, IRQ_TXIDLE); - - /* enable tx DMA */ - wr_reg32(info, TDCSR, BIT0); } - + tdma_start(info); info->tx_active = 1; } } +/* + * 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); + switch(info->params.mode) { + case MGSL_MODE_RAW: + case MGSL_MODE_MONOSYNC: + case MGSL_MODE_BISYNC: + wr_reg32(info, TDCSR, BIT2 + BIT0); /* IRQ + DMA enable */ + break; + default: + wr_reg32(info, TDCSR, BIT0); /* DMA enable */ + } +} + static void tx_stop(struct slgt_info *info) { unsigned short val; @@ -4642,8 +4659,8 @@ static unsigned int free_tbuf_count(struct slgt_info *info) i=0; } while (i != info->tbuf_current); - /* last buffer with zero count may be in use, assume it is */ - if (count) + /* if tx DMA active, last zero count buffer is in use */ + if (count && (rd_reg32(info, TDCSR) & BIT0)) --count; return count; |