From d314e9e80c5ea561b73584b73806c2ae9e30f503 Mon Sep 17 00:00:00 2001 From: Oliver Neukum Date: Wed, 23 Mar 2016 14:36:56 -0700 Subject: [PATCH] Input: sur40 - fix DMA on stack During the initialisation the driver uses a buffer on the stack for DMA. That violates the cache coherency rules. The fix is to allocate the buffer with kmalloc(). Signed-off-by: Oliver Neukum Signed-off-by: Dmitry Torokhov --- drivers/input/touchscreen/sur40.c | 21 ++++++++++++++------- 1 file changed, 14 insertions(+), 7 deletions(-) diff --git a/drivers/input/touchscreen/sur40.c b/drivers/input/touchscreen/sur40.c index b6c4d03de340..880c40b23f66 100644 --- a/drivers/input/touchscreen/sur40.c +++ b/drivers/input/touchscreen/sur40.c @@ -197,28 +197,34 @@ static int sur40_command(struct sur40_state *dev, static int sur40_init(struct sur40_state *dev) { int result; - u8 buffer[24]; + u8 *buffer; + + buffer = kmalloc(24, GFP_KERNEL); + if (!buffer) { + result = -ENOMEM; + goto error; + } /* stupidly replay the original MS driver init sequence */ result = sur40_command(dev, SUR40_GET_VERSION, 0x00, buffer, 12); if (result < 0) - return result; + goto error; result = sur40_command(dev, SUR40_GET_VERSION, 0x01, buffer, 12); if (result < 0) - return result; + goto error; result = sur40_command(dev, SUR40_GET_VERSION, 0x02, buffer, 12); if (result < 0) - return result; + goto error; result = sur40_command(dev, SUR40_UNKNOWN2, 0x00, buffer, 24); if (result < 0) - return result; + goto error; result = sur40_command(dev, SUR40_UNKNOWN1, 0x00, buffer, 5); if (result < 0) - return result; + goto error; result = sur40_command(dev, SUR40_GET_VERSION, 0x03, buffer, 12); @@ -226,7 +232,8 @@ static int sur40_init(struct sur40_state *dev) * Discard the result buffer - no known data inside except * some version strings, maybe extract these sometime... */ - +error: + kfree(buffer); return result; } -- 2.20.1