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yaml
---
r: 185178
b: refs/heads/master
c: de538eb
h: refs/heads/master
v: v3
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Paul Fulghum authored and Greg Kroah-Hartman committed Mar 2, 2010
1 parent 3c68d62 commit 145571d
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Showing 2 changed files with 106 additions and 82 deletions.
2 changes: 1 addition & 1 deletion [refs]
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Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: 8fe2d54145a51238308d333f9dc57c5df575ff78
refs/heads/master: de538eb3441e8b9f7aedb3a37e46c005538451dc
186 changes: 105 additions & 81 deletions trunk/drivers/char/synclink_gt.c
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Original file line number Diff line number Diff line change
Expand Up @@ -468,7 +468,7 @@ 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 tx_load(struct slgt_info *info, const char *buf, unsigned int count);
static bool tx_load(struct slgt_info *info, const char *buf, unsigned int count);

static void get_signals(struct slgt_info *info);
static void set_signals(struct slgt_info *info);
Expand Down Expand Up @@ -813,59 +813,32 @@ static int write(struct tty_struct *tty,
int ret = 0;
struct slgt_info *info = tty->driver_data;
unsigned long flags;
unsigned int bufs_needed;

if (sanity_check(info, tty->name, "write"))
goto cleanup;
return -EIO;

DBGINFO(("%s write count=%d\n", info->device_name, count));

if (!info->tx_buf)
goto cleanup;
if (!info->tx_buf || (count > info->max_frame_size))
return -EIO;

if (count > info->max_frame_size) {
ret = -EIO;
goto cleanup;
}
if (!count || tty->stopped || tty->hw_stopped)
return 0;

if (!count)
goto cleanup;
spin_lock_irqsave(&info->lock, flags);

if (!info->tx_active && info->tx_count) {
if (info->tx_count) {
/* send accumulated data from send_char() */
tx_load(info, info->tx_buf, info->tx_count);
goto start;
if (!tx_load(info, info->tx_buf, info->tx_count))
goto cleanup;
info->tx_count = 0;
}
bufs_needed = (count/DMABUFSIZE);
if (count % DMABUFSIZE)
++bufs_needed;
if (bufs_needed > free_tbuf_count(info))
goto cleanup;

ret = info->tx_count = count;
tx_load(info, buf, count);
goto start;

start:
if (info->tx_count && !tty->stopped && !tty->hw_stopped) {
spin_lock_irqsave(&info->lock,flags);
if (!info->tx_active)
tx_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);
}
if (tx_load(info, buf, count))
ret = count;

cleanup:
spin_unlock_irqrestore(&info->lock, flags);
DBGINFO(("%s write rc=%d\n", info->device_name, ret));
return ret;
}
Expand All @@ -882,7 +855,7 @@ static int put_char(struct tty_struct *tty, unsigned char ch)
if (!info->tx_buf)
return 0;
spin_lock_irqsave(&info->lock,flags);
if (!info->tx_active && (info->tx_count < info->max_frame_size)) {
if (info->tx_count < info->max_frame_size) {
info->tx_buf[info->tx_count++] = ch;
ret = 1;
}
Expand Down Expand Up @@ -981,10 +954,8 @@ static void flush_chars(struct tty_struct *tty)
DBGINFO(("%s flush_chars start transmit\n", info->device_name));

spin_lock_irqsave(&info->lock,flags);
if (!info->tx_active && info->tx_count) {
tx_load(info, info->tx_buf,info->tx_count);
tx_start(info);
}
if (info->tx_count && tx_load(info, info->tx_buf, info->tx_count))
info->tx_count = 0;
spin_unlock_irqrestore(&info->lock,flags);
}

Expand All @@ -997,10 +968,9 @@ static void flush_buffer(struct tty_struct *tty)
return;
DBGINFO(("%s flush_buffer\n", info->device_name));

spin_lock_irqsave(&info->lock,flags);
if (!info->tx_active)
info->tx_count = 0;
spin_unlock_irqrestore(&info->lock,flags);
spin_lock_irqsave(&info->lock, flags);
info->tx_count = 0;
spin_unlock_irqrestore(&info->lock, flags);

tty_wakeup(tty);
}
Expand Down Expand Up @@ -1033,12 +1003,10 @@ static void tx_release(struct tty_struct *tty)
if (sanity_check(info, tty->name, "tx_release"))
return;
DBGINFO(("%s tx_release\n", info->device_name));
spin_lock_irqsave(&info->lock,flags);
if (!info->tx_active && info->tx_count) {
tx_load(info, info->tx_buf, info->tx_count);
tx_start(info);
}
spin_unlock_irqrestore(&info->lock,flags);
spin_lock_irqsave(&info->lock, flags);
if (info->tx_count && tx_load(info, info->tx_buf, info->tx_count))
info->tx_count = 0;
spin_unlock_irqrestore(&info->lock, flags);
}

/*
Expand Down Expand Up @@ -1506,27 +1474,25 @@ static netdev_tx_t hdlcdev_xmit(struct sk_buff *skb,

DBGINFO(("%s hdlc_xmit\n", dev->name));

if (!skb->len)
return NETDEV_TX_OK;

/* stop sending until this frame completes */
netif_stop_queue(dev);

/* copy data to device buffers */
info->tx_count = skb->len;
tx_load(info, skb->data, skb->len);

/* update network statistics */
dev->stats.tx_packets++;
dev->stats.tx_bytes += skb->len;

/* done with socket buffer, so free it */
dev_kfree_skb(skb);

/* save start time for transmit timeout detection */
dev->trans_start = jiffies;

spin_lock_irqsave(&info->lock,flags);
tx_start(info);
update_tx_timer(info);
spin_unlock_irqrestore(&info->lock,flags);
spin_lock_irqsave(&info->lock, flags);
tx_load(info, skb->data, skb->len);
spin_unlock_irqrestore(&info->lock, flags);

/* done with socket buffer, so free it */
dev_kfree_skb(skb);

return NETDEV_TX_OK;
}
Expand Down Expand Up @@ -2180,7 +2146,7 @@ static void isr_serial(struct slgt_info *info)

if (info->params.mode == MGSL_MODE_ASYNC) {
if (status & IRQ_TXIDLE) {
if (info->tx_count)
if (info->tx_active)
isr_txeom(info, status);
}
if (info->rx_pio && (status & IRQ_RXDATA))
Expand Down Expand Up @@ -2276,13 +2242,42 @@ static void isr_tdma(struct slgt_info *info)
}
}

/*
* return true if there are unsent tx DMA buffers, otherwise false
*
* if there are unsent buffers then info->tbuf_start
* is set to index of first unsent buffer
*/
static bool unsent_tbufs(struct slgt_info *info)
{
unsigned int i = info->tbuf_current;
bool rc = false;

/*
* search backwards from last loaded buffer (precedes tbuf_current)
* for first unsent buffer (desc_count > 0)
*/

do {
if (i)
i--;
else
i = info->tbuf_count - 1;
if (!desc_count(info->tbufs[i]))
break;
info->tbuf_start = i;
rc = true;
} while (i != info->tbuf_current);

return rc;
}

static void isr_txeom(struct slgt_info *info, unsigned short status)
{
DBGISR(("%s txeom status=%04x\n", info->device_name, status));

slgt_irq_off(info, IRQ_TXDATA + IRQ_TXIDLE + IRQ_TXUNDER);
tdma_reset(info);
reset_tbufs(info);
if (status & IRQ_TXUNDER) {
unsigned short val = rd_reg16(info, TCR);
wr_reg16(info, TCR, (unsigned short)(val | BIT2)); /* set reset bit */
Expand All @@ -2297,8 +2292,12 @@ static void isr_txeom(struct slgt_info *info, unsigned short status)
info->icount.txok++;
}

if (unsent_tbufs(info)) {
tx_start(info);
update_tx_timer(info);
return;
}
info->tx_active = false;
info->tx_count = 0;

del_timer(&info->tx_timer);

Expand Down Expand Up @@ -3949,7 +3948,7 @@ static void tx_start(struct slgt_info *info)
info->tx_enabled = true;
}

if (info->tx_count) {
if (desc_count(info->tbufs[info->tbuf_start])) {
info->drop_rts_on_tx_done = false;

if (info->params.mode != MGSL_MODE_ASYNC) {
Expand Down Expand Up @@ -4772,25 +4771,36 @@ static unsigned int tbuf_bytes(struct slgt_info *info)
}

/*
* load transmit DMA buffer(s) with data
* load data into transmit DMA buffer ring and start transmitter if needed
* return true if data accepted, otherwise false (buffers full)
*/
static void tx_load(struct slgt_info *info, const char *buf, unsigned int size)
static bool tx_load(struct slgt_info *info, const char *buf, unsigned int size)
{
unsigned short count;
unsigned int i;
struct slgt_desc *d;

if (size == 0)
return;
/* check required buffer space */
if (DIV_ROUND_UP(size, DMABUFSIZE) > free_tbuf_count(info))
return false;

DBGDATA(info, buf, size, "tx");

/*
* copy data to one or more DMA buffers in circular ring
* tbuf_start = first buffer for this data
* tbuf_current = next free buffer
*
* Copy all data before making data visible to DMA controller by
* setting descriptor count of the first buffer.
* This prevents an active DMA controller from reading the first DMA
* buffers of a frame and stopping before the final buffers are filled.
*/

info->tbuf_start = i = info->tbuf_current;

while (size) {
d = &info->tbufs[i];
if (++i == info->tbuf_count)
i = 0;

count = (unsigned short)((size > DMABUFSIZE) ? DMABUFSIZE : size);
memcpy(d->buf, buf, count);
Expand All @@ -4808,11 +4818,27 @@ static void tx_load(struct slgt_info *info, const char *buf, unsigned int size)
else
set_desc_eof(*d, 0);

set_desc_count(*d, count);
/* set descriptor count for all but first buffer */
if (i != info->tbuf_start)
set_desc_count(*d, count);
d->buf_count = count;

if (++i == info->tbuf_count)
i = 0;
}

info->tbuf_current = i;

/* set first buffer count to make new data visible to DMA controller */
d = &info->tbufs[info->tbuf_start];
set_desc_count(*d, d->buf_count);

/* start transmitter if needed and update transmit timeout */
if (!info->tx_active)
tx_start(info);
update_tx_timer(info);

return true;
}

static int register_test(struct slgt_info *info)
Expand Down Expand Up @@ -4934,9 +4960,7 @@ static int loopback_test(struct slgt_info *info)
spin_lock_irqsave(&info->lock,flags);
async_mode(info);
rx_start(info);
info->tx_count = count;
tx_load(info, buf, count);
tx_start(info);
spin_unlock_irqrestore(&info->lock, flags);

/* wait for receive complete */
Expand Down

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