[PATCH 2/4] HID: lg: make transfer buffers DMA capable

[Benjamin Tissoires]

Kernel v4.9 strictly enforces DMA capable buffers, so we need to remove
buffers allocated on the stack.

Signed-off-by: Benjamin Tissoires <benjamin.tissoi...@redhat.com>
---
 drivers/hid/hid-lg.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/hid/hid-lg.c b/drivers/hid/hid-lg.c
index 76f644d..d4c72a5 100644
--- a/drivers/hid/hid-lg.c
+++ b/drivers/hid/hid-lg.c
@@ -756,11 +756,16 @@ static int lg_probe(struct hid_device *hdev, const struct 
hid_device_id *id)
 
        /* Setup wireless link with Logitech Wii wheel */
        if (hdev->product == USB_DEVICE_ID_LOGITECH_WII_WHEEL) {
-               unsigned char buf[] = { 0x00, 0xAF,  0x01, 0x00, 0x00, 0x00, 
0x00, 0x00, 0x00 };
+               const unsigned char cbuf[] = { 0x00, 0xAF,  0x01, 0x00, 0x00, 
0x00, 0x00, 0x00, 0x00 };
+               u8 *buf = kmemdup(cbuf, sizeof(cbuf), GFP_KERNEL);
 
-               ret = hid_hw_raw_request(hdev, buf[0], buf, sizeof(buf),
-                                       HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
+               if (!buf) {
+                       ret = -ENOMEM;
+                       goto err_free;
+               }
 
+               ret = hid_hw_raw_request(hdev, buf[0], buf, sizeof(cbuf),
+                                       HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
                if (ret >= 0) {
                        /* insert a little delay of 10 jiffies ~ 40ms */
                        wait_queue_head_t wait;
@@ -775,6 +780,7 @@ static int lg_probe(struct hid_device *hdev, const struct 
hid_device_id *id)
                        ret = hid_hw_raw_request(hdev, buf[0], buf, sizeof(buf),
                                        HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
                }
+               kfree(buf);
        }
 
        if (drv_data->quirks & LG_FF)
-- 
2.7.4