tty: bring the old cris driver back somewhere into the realm of new tty buffering

Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Mikael Starvik <starvik@axis.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 12 insertions, 55 deletions

diff --git a/drivers/serial/crisv10.c b/drivers/serial/crisv10.c
index 312bef6bd583..7e8724d3571f 100644
--- a/drivers/serial/crisv10.c
+++ b/drivers/serial/crisv10.c
@@ -514,6 +514,8 @@ struct tty_driver *serial_driver;
  * TTY_THRESHOLD_THROTTLE/UNTHROTTLE=128
  * BUF_SIZE can't be > 128
  */
+#define CRIS_BUF_SIZE   512
+
 /* Currently 16 descriptors x 128 bytes = 2048 bytes */
 #define SERIAL_DESCR_BUF_SIZE 256
 
@@ -2497,55 +2499,18 @@ static void flush_to_flip_buffer(struct e100_serial *info)
                 return;
         }
 
-        length = tty->flip.count;
-        /* Don't flip more than the ldisc has room for.
-         * The return value from ldisc.receive_room(tty) - might not be up to
-         * date, the previous flip of up to TTY_FLIPBUF_SIZE might be on the
-         * processed and not accounted for yet.
-         * Since we use DMA, 1 SERIAL_DESCR_BUF_SIZE could be on the way.
-         * Lets buffer data here and let flow control take care of it.
-         * Since we normally flip large chunks, the ldisc don't react
-         * with throttle until too late if we flip to much.
-         */
-        max_flip_size = tty->ldisc.receive_room(tty);
-        if (max_flip_size < 0)
-                max_flip_size = 0;
-        if (max_flip_size <= (TTY_FLIPBUF_SIZE +         /* Maybe not accounted for */
-                              length + info->recv_cnt +  /* We have this queued */
-                              2*SERIAL_DESCR_BUF_SIZE +    /* This could be on the way */
-                              TTY_THRESHOLD_THROTTLE)) { /* Some slack */
-                /* check TTY_THROTTLED first so it indicates our state */
-                if (!test_and_set_bit(TTY_THROTTLED, &tty->flags)) {
-                        DFLOW(DEBUG_LOG(info->line,"flush_to_flip throttles room %lu\n", max_flip_size));
-                        rs_throttle(tty);
-                }
-#if 0
-                else if (max_flip_size <= (TTY_FLIPBUF_SIZE +         /* Maybe not accounted for */
-                                           length + info->recv_cnt +  /* We have this queued */
-                                           SERIAL_DESCR_BUF_SIZE +    /* This could be on the way */
-                                           TTY_THRESHOLD_THROTTLE)) { /* Some slack */
-                        DFLOW(DEBUG_LOG(info->line,"flush_to_flip throttles again! %lu\n", max_flip_size));
-                        rs_throttle(tty);
-                }
-#endif
-        }
-
-        if (max_flip_size > TTY_FLIPBUF_SIZE)
-                max_flip_size = TTY_FLIPBUF_SIZE;
-
-        while ((buffer = info->first_recv_buffer) && length < max_flip_size) {
+        while ((buffer = info->first_recv_buffer) != NULL) {
                 unsigned int count = buffer->length;
 
-                if (length + count > max_flip_size)
-                        count = max_flip_size - length;
+                count = tty_buffer_request_room(tty, count);
+                if (count == 0) /* Throttle ?? */
+                        break;
 
-                memcpy(tty->flip.char_buf_ptr + length, buffer->buffer, count);
-                memset(tty->flip.flag_buf_ptr + length, TTY_NORMAL, count);
-                tty->flip.flag_buf_ptr[length] = buffer->error;
+                if (count > 1)
+                        tty_insert_flip_strings(tty, buffer->buffer, count - 1);
+                tty_insert_flip_char(tty, buffer->buffer[count-1], buffer->error);
 
-                length += count;
                 info->recv_cnt -= count;
-                DFLIP(DEBUG_LOG(info->line,"flip: %i\n", length));
 
                 if (count == buffer->length) {
                         info->first_recv_buffer = buffer->next;
@@ -2560,14 +2525,6 @@ static void flush_to_flip_buffer(struct e100_serial *info)
         if (!info->first_recv_buffer)
                 info->last_recv_buffer = NULL;
 
-        tty->flip.count = length;
-        DFLIP(if (tty->ldisc.chars_in_buffer(tty) > 3500) {
-                DEBUG_LOG(info->line, "ldisc %lu\n",
-                          tty->ldisc.chars_in_buffer(tty));
-                DEBUG_LOG(info->line, "flip.count %lu\n",
-                          tty->flip.count);
-              }
-              );
         restore_flags(flags);
 
         DFLIP(
@@ -2722,17 +2679,17 @@ struct e100_serial * handle_ser_rx_interrupt_no_dma(struct e100_serial *info)
                 printk("!NO TTY!\n");
                 return info;
         }
-        if (tty->flip.count >= TTY_FLIPBUF_SIZE - TTY_THRESHOLD_THROTTLE) {
+        if (tty->flip.count >= CRIS_BUF_SIZE - TTY_THRESHOLD_THROTTLE) {
                 /* check TTY_THROTTLED first so it indicates our state */
                 if (!test_and_set_bit(TTY_THROTTLED, &tty->flags)) {
                         DFLOW(DEBUG_LOG(info->line, "rs_throttle flip.count: %i\n", tty->flip.count));
                         rs_throttle(tty);
                 }
         }
-        if (tty->flip.count >= TTY_FLIPBUF_SIZE) {
+        if (tty->flip.count >= CRIS_BUF_SIZE) {
                 DEBUG_LOG(info->line, "force FLIP! %i\n", tty->flip.count);
                 tty->flip.work.func((void *) tty);
-                if (tty->flip.count >= TTY_FLIPBUF_SIZE) {
+                if (tty->flip.count >= CRIS_BUF_SIZE) {
                         DEBUG_LOG(info->line, "FLIP FULL! %i\n", tty->flip.count);
                         return info;            /* if TTY_DONT_FLIP is set */
                 }