From ba172c70451ed6688a31e27d8bb5a4631c2003de Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Fri, 21 Aug 2015 20:02:53 +0200 Subject: [PATCH] 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 Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/sh-sci.c | 26 ++++++++++++-------------- 1 file changed, 12 insertions(+), 14 deletions(-) diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index 57b1cc1da67d..681e52a087c2 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -1734,18 +1734,16 @@ static void sci_request_dma(struct uart_port *port) 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 @@ static void sci_request_dma(struct uart_port *port) 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); -- 2.39.2