Changeset 281 for GPL/branches/alsa-resync1/alsa-kernel/drivers/serial-u16550.c

Timestamp:

Jan 23, 2008, 7:05:10 AM (18 years ago)

Author:

Brendan Oakley

Message:

Merged to ALSA 1.0.1

File:

• GPL/branches/alsa-resync1/alsa-kernel/drivers/serial-u16550.c (modified) (21 diffs)

GPL/branches/alsa-resync1/alsa-kernel/drivers/serial-u16550.c

@@ -64 +64 @@
 };
 
+#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 */
@@ -75 +78 @@
 static int ins[SNDRV_CARDS] = {REPEAT_SNDRV(1)};        /* 1 to 16 */
 static int adaptor[SNDRV_CARDS] = {REPEAT_SNDRV(SNDRV_SERIAL_SOUNDCANVAS)};
+static int droponfull[SNDRV_CARDS] = {REPEAT_SNDRV(SNDRV_SERIAL_NORMALBUFF)};
 #else
 static int speed[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 38400}; /* 9600,19200,38400,57600,115200 */
@@ -81 +85 @@
 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 };
 #endif
 
@@ -108 +113 @@
 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");
@@ -172 +180 @@
     int buff_in;
     int buff_out;
+        int drop_on_full;
 
     // wait timer
@@ -203 +212 @@
 {
     unsigned short buff_out = uart->buff_out;
+        if( uart->buff_in_count > 0 ) {
     outb(uart->tx_buff[buff_out], uart->base + UART_TX);
     uart->fifo_count++;
@@ -209 +219 @@
     uart->buff_out = buff_out;
     uart->buff_in_count--;
+        }
 }
 
@@ -266 +277 @@
         /* 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)
+                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 */
@@ -585 +598 @@
 };
 
-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;
+        if( uart->buff_in_count < TX_BUFF_SIZE ) {
     uart->tx_buff[buff_in] = byte;
     buff_in++;
@@ -594 +616 @@
     uart->buff_in_count++;
     if (uart->irq < 0) /* polling mode */
-        snd_uart16550_add_timer(uart);
-}
-
-static void snd_uart16550_output_byte(snd_uart16550_t *uart, snd_rawmidi_substream_t * substream, unsigned char midi_byte)
+                        snd_uart16550_add_timer(uart);
+                return 1;
+        } else
+                return 0;
+}
+
+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? */
@@ -620 +645 @@
         }
     } 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;
-        }
-        snd_uart16550_write_buffer(uart, midi_byte);
-    }
+                        return 0;
+                }
+        }
+
+        return 1;
 }
 
@@ -670 +696 @@
     } 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 ||
@@ -678 +702 @@
                            (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)
-                                        break;
-
+                                if( snd_uart16550_buffer_can_write( uart, 3 ) ) {
                 /* Roland Soundcanvas part selection */
                 /* If this substream of the data is different previous
@@ -693 +714 @@
                                 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)
+                                } else if( !uart->drop_on_full )
+                                        break;
+
+                        }
+
+            /* 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;
@@ -780 +804 @@
                                        unsigned int base,
                                        int adaptor,
+                                       int droponfull,
                                        snd_uart16550_t **ruart)
 {
@@ -796 +821 @@
     uart->irq = -1;
     uart->base = iobase;
+        uart->drop_on_full = droponfull;
 
         if ((err = snd_uart16550_detect(uart)) <= 0) {
@@ -925 +951 @@
                                         base[dev],
                                         adaptor[dev],
+                                        droponfull[dev],
                                     &uart)) < 0) {
         snd_card_free(card);
@@ -935 +962 @@
     }
 
-        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,
@@ -943 +970 @@
                 outs[dev],
                 ins[dev],
-            adaptor_names[uart->adaptor]);
+                adaptor_names[uart->adaptor],
+                uart->drop_on_full);
 
     if ((err = snd_card_register(card)) < 0) {
@@ -989 +1017 @@
 /* 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)
@@ -1006 +1034 @@
                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;