serial: sh-sci: Pass scatterlist to sci_dma_rx_push()

Currently sci_dma_rx_push() has to find the active scatterlist itself,
but in some cases the caller already knows.

Hence let the caller pass the scatterlist, and introduce a helper to
find the active DMA request while we're at it.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index 35e24b726fe605d13f91d1110a78991d183b86fe..2b44004e5115fa59ad880994a2e49b2a56266d5a 100644 (file)
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -1301,24 +1301,15 @@ static void sci_dma_tx_complete(void *arg)
 }
 
 /* Locking: called with port lock held */
-static int sci_dma_rx_push(struct sci_port *s, size_t count)
+static int sci_dma_rx_push(struct sci_port *s, struct scatterlist *sg,
+                          size_t count)
 {
        struct uart_port *port = &s->port;
        struct tty_port *tport = &port->state->port;
-       int i, active, room;
+       int i, room;
 
        room = tty_buffer_request_room(tport, count);
 
-       if (s->active_rx == s->cookie_rx[0]) {
-               active = 0;
-       } else if (s->active_rx == s->cookie_rx[1]) {
-               active = 1;
-       } else {
-               dev_err(port->dev, "%s: Rx cookie %d not found!\n", __func__,
-                       s->active_rx);
-               return 0;
-       }
-
        if (room < count)
                dev_warn(port->dev, "Rx overrun: dropping %zu bytes\n",
                         count - room);
@@ -1326,27 +1317,41 @@ static int sci_dma_rx_push(struct sci_port *s, size_t count)
                return room;
 
        for (i = 0; i < room; i++)
-               tty_insert_flip_char(tport, ((u8 *)sg_virt(&s->sg_rx[active]))[i],
-                                    TTY_NORMAL);
+               tty_insert_flip_char(tport, ((u8 *)sg_virt(sg))[i], TTY_NORMAL);
 
        port->icount.rx += room;
 
        return room;
 }
 
+static int sci_dma_rx_find_active(struct sci_port *s)
+{
+       unsigned int i;
+
+       for (i = 0; i < ARRAY_SIZE(s->cookie_rx); i++)
+               if (s->active_rx == s->cookie_rx[i])
+                       return i;
+
+       dev_err(s->port.dev, "%s: Rx cookie %d not found!\n", __func__,
+               s->active_rx);
+       return -1;
+}
+
 static void sci_dma_rx_complete(void *arg)
 {
        struct sci_port *s = arg;
        struct uart_port *port = &s->port;
        unsigned long flags;
-       int count;
+       int active, count = 0;
 
        dev_dbg(port->dev, "%s(%d) active cookie %d\n", __func__, port->line,
                s->active_rx);
 
        spin_lock_irqsave(&port->lock, flags);
 
-       count = sci_dma_rx_push(s, s->buf_len_rx);
+       active = sci_dma_rx_find_active(s);
+       if (active >= 0)
+               count = sci_dma_rx_push(s, &s->sg_rx[active], s->buf_len_rx);
 
        mod_timer(&s->rx_timer, jiffies + s->rx_timeout);
 
@@ -1445,13 +1450,8 @@ static void work_fn_rx(struct work_struct *work)
        int new;
 
        spin_lock_irqsave(&port->lock, flags);
-       if (s->active_rx == s->cookie_rx[0]) {
-               new = 0;
-       } else if (s->active_rx == s->cookie_rx[1]) {
-               new = 1;
-       } else {
-               dev_err(port->dev, "%s: Rx cookie %d not found!\n", __func__,
-                       s->active_rx);
+       new = sci_dma_rx_find_active(s);
+       if (new < 0) {
                spin_unlock_irqrestore(&port->lock, flags);
                return;
        }
@@ -1468,7 +1468,7 @@ static void work_fn_rx(struct work_struct *work)
                dev_dbg(port->dev, "Read %u bytes with cookie %d\n", read,
                        s->active_rx);
 
-               count = sci_dma_rx_push(s, read);
+               count = sci_dma_rx_push(s, &s->sg_rx[new], read);
 
                if (count)
                        tty_flip_buffer_push(&port->state->port);