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Add missing implementation of O_NONBLOCK for serial writes

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git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@5755 42af7a65-404d-4744-a932-0658087f49c3
This commit is contained in:
patacongo
2013-03-18 16:04:29 +00:00
parent 1a67cb9e1e
commit 730dc3e202
2 changed files with 36 additions and 6 deletions
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drivers/serial/serial.c
+30 -6
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@@ -178,7 +178,7 @@ static void uart_pollnotify(FAR uart_dev_t *dev, pollevent_t eventset)
* Name: uart_putxmitchar
************************************************************************************/
static int uart_putxmitchar(FAR uart_dev_t *dev, int ch)
static int uart_putxmitchar(FAR uart_dev_t *dev, int ch, bool oktoblock)
{
irqstate_t flags;
int nexthead;
@@ -204,7 +204,13 @@ static int uart_putxmitchar(FAR uart_dev_t *dev, int ch)
dev->xmit.head = nexthead;
return OK;
}
else
/* The buffer is full and no data is available now. Should be block,
* waiting for the the hardware to remove some data from the TX
* buffer?
*/
else if (oktoblock)
{
/* Inform the interrupt level logic that we are waiting. This and
* the following steps must be atomic.
@@ -260,6 +266,15 @@ static int uart_putxmitchar(FAR uart_dev_t *dev, int ch)
return -EINTR;
}
}
/* The caller has request that we not block for data. So return the
* EAGAIN error to signal this situation.
*/
else
{
return -EAGAIN;
}
}
/* We won't get here. Some compilers may complain that this code is
@@ -307,6 +322,7 @@ static ssize_t uart_write(FAR struct file *filep, FAR const char *buffer, size_t
FAR struct inode *inode = filep->f_inode;
FAR uart_dev_t *dev = inode->i_private;
ssize_t nread = buflen;
bool oktoblock;
int ret;
/* We may receive console writes through this path from interrupt handlers and
@@ -371,6 +387,12 @@ static ssize_t uart_write(FAR struct file *filep, FAR const char *buffer, size_t
}
#endif
/* Can the following loop block, waiting for space in the TX
* buffer?
*/
oktoblock = ((filep->f_oflags & O_NONBLOCK) == 0);
/* Loop while we still have data to copy to the transmit buffer.
* we add data to the head of the buffer; uart_xmitchars takes the
* data from the end of the buffer.
@@ -386,22 +408,24 @@ static ssize_t uart_write(FAR struct file *filep, FAR const char *buffer, size_t
ret = OK;
if (dev->isconsole && ch == '\n')
{
ret = uart_putxmitchar(dev, '\r');
ret = uart_putxmitchar(dev, '\r', oktoblock);
}
/* Put the character into the transmit buffer */
if (ret == OK)
{
ret = uart_putxmitchar(dev, ch);
ret = uart_putxmitchar(dev, ch, oktoblock);
}
/* uart_putxmitchar() might return an error under one of two
* conditions: (1) The wait for buffer space might have been
* interrupted by a signal (ret should be -EINTR), or (2) if
* interrupted by a signal (ret should be -EINTR), (2) if
* CONFIG_SERIAL_REMOVABLE is defined, then uart_putxmitchar()
* might also return if the serial device was disconnected
* (with -ENOTCONN).
* (with -ENOTCONN), or (3) if O_NONBLOCK is specified, then
* then uart_putxmitchar() might return -EAGAIN if the output
* TX buffer is full.
*/
if (ret < 0)