serial: sh-sci: Use incrementing pointers instead of stack array
There's no need to keep all buffer and DMA pointers on the stack.
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 57b1cc1..681e52a 100644
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -1734,18 +1734,16 @@
chan = dma_request_channel(mask, filter, param);
dev_dbg(port->dev, "%s: RX: got channel %p\n", __func__, chan);
if (chan) {
- dma_addr_t dma[2];
- void *buf[2];
- int i;
+ unsigned int i;
+ dma_addr_t dma;
+ void *buf;
s->chan_rx = chan;
s->buf_len_rx = 2 * max_t(size_t, 16, port->fifosize);
- buf[0] = dma_alloc_coherent(chan->device->dev,
- s->buf_len_rx * 2, &dma[0],
- GFP_KERNEL);
-
- if (!buf[0]) {
+ buf = dma_alloc_coherent(chan->device->dev, s->buf_len_rx * 2,
+ &dma, GFP_KERNEL);
+ if (!buf) {
dev_warn(port->dev,
"Failed to allocate Rx dma buffer, using PIO\n");
dma_release_channel(chan);
@@ -1754,16 +1752,16 @@
return;
}
- buf[1] = buf[0] + s->buf_len_rx;
- dma[1] = dma[0] + s->buf_len_rx;
-
for (i = 0; i < 2; i++) {
struct scatterlist *sg = &s->sg_rx[i];
sg_init_table(sg, 1);
- sg_set_page(sg, virt_to_page(buf[i]), s->buf_len_rx,
- (uintptr_t)buf[i] & ~PAGE_MASK);
- sg_dma_address(sg) = dma[i];
+ sg_set_page(sg, virt_to_page(buf), s->buf_len_rx,
+ (uintptr_t)buf & ~PAGE_MASK);
+ sg_dma_address(sg) = dma;
+
+ buf += s->buf_len_rx;
+ dma += s->buf_len_rx;
}
INIT_WORK(&s->work_rx, work_fn_rx);