Update of /cvsroot/alsa/alsa-kernel/drivers
In directory sc8-pr-cvs1:/tmp/cvs-serv25373
Modified Files:
serial-u16550.c
Log Message:
Steve deRosier <[EMAIL PROTECTED]>:
* There is a user selectable flag "droponfull". Set to 1 and
any new bytes delivered to the driver after the buffer fills
up will be discarded until the buffer is able to flush some
bytes.
* If droponfull==0 (or is not set, the default is 0), the driver
proceeds to block further input by not calling
snd_rawmidi_transmit_ack() and aborting the attempt. It will
try again later.
* I've redone a bit of the interface for the buffer routines.
This was done to support the proper blocking/non-blocking methods
as spelled out above, and to try to protect the buffer data a bit.
Index: serial-u16550.c
===================================================================
RCS file: /cvsroot/alsa/alsa-kernel/drivers/serial-u16550.c,v
retrieving revision 1.22
retrieving revision 1.23
diff -u -r1.22 -r1.23
--- serial-u16550.c 14 Oct 2003 13:08:13 -0000 1.22
+++ serial-u16550.c 3 Dec 2003 13:23:22 -0000 1.23
@@ -63,6 +63,9 @@
"Generic"
};
+#define SNDRV_SERIAL_NORMALBUFF 0 /* Normal blocking buffer operation */
+#define SNDRV_SERIAL_DROPBUFF 1 /* Non-blocking discard operation */
+
static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX; /* Index 0-MAX */
static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR; /* ID for this card */
static int enable[SNDRV_CARDS] = SNDRV_DEFAULT_ENABLE; /* Enable this card */
@@ -73,6 +76,7 @@
static int outs[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 1}; /* 1 to 16 */
static int ins[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 1}; /* 1 to 16 */
static int adaptor[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] =
SNDRV_SERIAL_SOUNDCANVAS};
+static int droponfull[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS -1)] =
SNDRV_SERIAL_NORMALBUFF };
MODULE_PARM(index, "1-" __MODULE_STRING(SNDRV_CARDS) "i");
MODULE_PARM_DESC(index, "Index value for Serial MIDI.");
@@ -99,6 +103,9 @@
MODULE_PARM_DESC(outs, "Number of MIDI outputs.");
MODULE_PARM(ins, "1-" __MODULE_STRING(SNDRV_CARDS) "i");
MODULE_PARM_DESC(ins, "Number of MIDI inputs.");
+MODULE_PARM(droponfull, "1-" __MODULE_STRING(SNDRV_CARDS) "i");
+MODULE_PARM_DESC(droponfull, "Flag to enable drop-on-full buffer mode");
+MODULE_PARM_SYNTAX(droponfull, SNDRV_ENABLED "," SNDRV_BOOLEAN_FALSE_DESC);
MODULE_PARM_SYNTAX(outs, SNDRV_ENABLED ",allows:{{1,16}},dialog:list");
MODULE_PARM_SYNTAX(ins, SNDRV_ENABLED ",allows:{{1,16}},dialog:list");
@@ -163,6 +170,7 @@
int buff_in_count;
int buff_in;
int buff_out;
+ int drop_on_full;
// wait timer
unsigned int timer_running:1;
@@ -194,12 +202,14 @@
inline static void snd_uart16550_buffer_output(snd_uart16550_t *uart)
{
unsigned short buff_out = uart->buff_out;
- outb(uart->tx_buff[buff_out], uart->base + UART_TX);
- uart->fifo_count++;
- buff_out++;
- buff_out &= TX_BUFF_MASK;
- uart->buff_out = buff_out;
- uart->buff_in_count--;
+ if( uart->buff_in_count > 0 ) {
+ outb(uart->tx_buff[buff_out], uart->base + UART_TX);
+ uart->fifo_count++;
+ buff_out++;
+ buff_out &= TX_BUFF_MASK;
+ uart->buff_out = buff_out;
+ uart->buff_in_count--;
+ }
}
/* This loop should be called with interrupts disabled
@@ -257,9 +267,11 @@
|| uart->adaptor == SNDRV_SERIAL_GENERIC) {
/* Can't use FIFO, must send only when CTS is true */
status = inb(uart->base + UART_MSR);
- if (uart->fifo_count == 0 && (status & UART_MSR_CTS)
- && uart->buff_in_count > 0)
- snd_uart16550_buffer_output(uart);
+ while( (uart->fifo_count == 0) && (status & UART_MSR_CTS) &&
+ (uart->buff_in_count > 0) ) {
+ snd_uart16550_buffer_output(uart);
+ status = inb( uart->base + UART_MSR );
+ }
} else {
/* Write loop */
while (uart->fifo_count < uart->fifo_limit /* Can we write ? */
@@ -576,19 +588,31 @@
return 0;
};
-inline static void snd_uart16550_write_buffer(snd_uart16550_t *uart, unsigned char
byte)
+inline static int snd_uart16550_buffer_can_write( snd_uart16550_t *uart, int Num )
+{
+ if( uart->buff_in_count + Num < TX_BUFF_SIZE )
+ return 1;
+ else
+ return 0;
+}
+
+inline static int snd_uart16550_write_buffer(snd_uart16550_t *uart, unsigned char
byte)
{
unsigned short buff_in = uart->buff_in;
- uart->tx_buff[buff_in] = byte;
- buff_in++;
- buff_in &= TX_BUFF_MASK;
- uart->buff_in = buff_in;
- uart->buff_in_count++;
- if (uart->irq < 0) /* polling mode */
- snd_uart16550_add_timer(uart);
+ if( uart->buff_in_count < TX_BUFF_SIZE ) {
+ uart->tx_buff[buff_in] = byte;
+ buff_in++;
+ buff_in &= TX_BUFF_MASK;
+ uart->buff_in = buff_in;
+ uart->buff_in_count++;
+ if (uart->irq < 0) /* polling mode */
+ snd_uart16550_add_timer(uart);
+ return 1;
+ } else
+ return 0;
}
-static void snd_uart16550_output_byte(snd_uart16550_t *uart, snd_rawmidi_substream_t
* substream, unsigned char midi_byte)
+static int snd_uart16550_output_byte(snd_uart16550_t *uart, snd_rawmidi_substream_t *
substream, unsigned char midi_byte)
{
if (uart->buff_in_count == 0 /* Buffer empty? */
&& ((uart->adaptor != SNDRV_SERIAL_MS124W_SA &&
@@ -611,13 +635,14 @@
}
}
} else {
- if (uart->buff_in_count >= TX_BUFF_SIZE) {
+ if( !snd_uart16550_write_buffer(uart, midi_byte) ) {
snd_printk("%s: Buffer overrun on device at 0x%lx\n",
uart->rmidi->name, uart->base);
- return;
+ return 0;
}
- snd_uart16550_write_buffer(uart, midi_byte);
}
+
+ return 1;
}
static void snd_uart16550_output_write(snd_rawmidi_substream_t * substream)
@@ -661,40 +686,38 @@
}
} else {
first = 0;
- while (1) {
- if (snd_rawmidi_transmit(substream, &midi_byte, 1) != 1)
- break;
+ while( 1 == snd_rawmidi_transmit_peek(substream, &midi_byte, 1) ) {
/* Also send F5 after 3 seconds with no data to handle device
disconnect */
if (first == 0 && (uart->adaptor == SNDRV_SERIAL_SOUNDCANVAS ||
uart->adaptor == SNDRV_SERIAL_GENERIC) &&
(uart->prev_out != substream->number || jiffies-lasttime >
3*HZ)) {
- /* We will need three bytes of data here (worst case).
*/
- if (uart->buff_in_count >= TX_BUFF_SIZE - 3)
+ if( snd_uart16550_buffer_can_write( uart, 3 ) ) {
+ /* Roland Soundcanvas part selection */
+ /* If this substream of the data is different
previous
+ substream in this uart, send the change
part event */
+ uart->prev_out = substream->number;
+ /* change part */
+ snd_uart16550_output_byte(uart, substream,
0xf5);
+ /* data */
+ snd_uart16550_output_byte(uart, substream,
uart->prev_out + 1);
+ /* If midi_byte is a data byte, send the
previous status byte */
+ if ((midi_byte < 0x80) && (uart->adaptor ==
SNDRV_SERIAL_SOUNDCANVAS))
+ snd_uart16550_output_byte(uart,
substream, uart->prev_status[uart->prev_out]);
+ } else if( !uart->drop_on_full )
break;
- /* Roland Soundcanvas part selection */
- /* If this substream of the data is different previous
- substream in this uart, send the change part event
*/
- uart->prev_out = substream->number;
- /* change part */
- snd_uart16550_output_byte(uart, substream, 0xf5);
- /* data */
- snd_uart16550_output_byte(uart, substream,
uart->prev_out + 1);
- /* If midi_byte is a data byte, send the previous
status byte */
- if ((midi_byte < 0x80) && (uart->adaptor ==
SNDRV_SERIAL_SOUNDCANVAS))
- snd_uart16550_output_byte(uart, substream,
uart->prev_status[uart->prev_out]);
}
- /* buffer full? */
- if (uart->buff_in_count >= TX_BUFF_SIZE)
+ /* send midi byte */
+ if( !snd_uart16550_output_byte(uart, substream, midi_byte) &&
!uart->drop_on_full )
break;
- /* send midi byte */
- snd_uart16550_output_byte(uart, substream, midi_byte);
if (midi_byte >= 0x80 && midi_byte < 0xf0)
uart->prev_status[uart->prev_out] = midi_byte;
first = 1;
+
+ snd_rawmidi_transmit_ack( substream, 1 );
}
lasttime = jiffies;
}
@@ -755,6 +778,7 @@
unsigned int speed,
unsigned int base,
int adaptor,
+ int droponfull,
snd_uart16550_t **ruart)
{
static snd_device_ops_t ops = {
@@ -771,6 +795,7 @@
spin_lock_init(&uart->open_lock);
uart->irq = -1;
uart->base = iobase;
+ uart->drop_on_full = droponfull;
if ((err = snd_uart16550_detect(uart)) <= 0) {
printk(KERN_ERR "no UART detected at 0x%lx\n", iobase);
@@ -900,6 +925,7 @@
speed[dev],
base[dev],
adaptor[dev],
+ droponfull[dev],
&uart)) < 0) {
snd_card_free(card);
return err;
@@ -910,7 +936,7 @@
return err;
}
- sprintf(card->longname, "%s at 0x%lx, irq %d speed %d div %d outs %d ins %d
adaptor %s",
+ sprintf(card->longname, "%s at 0x%lx, irq %d speed %d div %d outs %d ins %d
adaptor %s droponfull %d",
card->shortname,
uart->base,
uart->irq,
@@ -918,7 +944,8 @@
(int)uart->divisor,
outs[dev],
ins[dev],
- adaptor_names[uart->adaptor]);
+ adaptor_names[uart->adaptor],
+ uart->drop_on_full);
if ((err = snd_card_register(card)) < 0) {
snd_card_free(card);
@@ -964,7 +991,7 @@
/* format is: snd-serial=enable,index,id,
port,irq,speed,base,outs,
- ins,adaptor */
+ ins,adaptor,droponfull */
static int __init alsa_card_serial_setup(char *str)
{
@@ -981,7 +1008,8 @@
get_option(&str,&base[nr_dev]) == 2 &&
get_option(&str,&outs[nr_dev]) == 2 &&
get_option(&str,&ins[nr_dev]) == 2 &&
- get_option(&str,&adaptor[nr_dev]) == 2);
+ get_option(&str,&adaptor[nr_dev]) == 2 &&
+ get_option(&str,&droponfull[nr_dev]) == 2 );
nr_dev++;
return 1;
}
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