2014-11-07 14:15:12

by Andrew Jackson

[permalink] [raw]
Subject: [PATCH 1/5] serial: pl011: Allocate TX DMA buffer from DMA capable memory


Allocating with __GFP_DMA avoids the need for bounce buffers

Signed-off-by: Andrew Jackson <[email protected]>
---
drivers/tty/serial/amba-pl011.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index 8572f2a..a285196 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -987,7 +987,7 @@ static void pl011_dma_startup(struct uart_amba_port *uap)
if (!uap->dmatx.chan)
return;

- uap->dmatx.buf = kmalloc(PL011_DMA_BUFFER_SIZE, GFP_KERNEL);
+ uap->dmatx.buf = kmalloc(PL011_DMA_BUFFER_SIZE, GFP_KERNEL | __GFP_DMA);
if (!uap->dmatx.buf) {
dev_err(uap->port.dev, "no memory for DMA TX buffer\n");
uap->port.fifosize = uap->fifosize;
--
1.7.1