On Mar 28 2016 or thereabouts, Josh Boyer wrote:
> The lenovo_send_cmd_cptkbd function uses a stack variable to submit
> commands via hid_hw_raw_request. Eventually this gets to the
> usb_hcd_map_urb_for_dma function, which causes a warning to be thrown
> if the CONFIG_DMA_API_DEBUG option is enabled.
>
> Fix this by allocating a temporary buffer instead.
>
> Reported-by: lejeczek <pelj...@yahoo.co.uk>
> Signed-off-by: Josh Boyer <jwbo...@fedoraproject.org>
> ---
The patch is
Reviewed-by: Benjamin Tissoires <benjamin.tissoi...@redhat.com>
There is just one nitpick that can be solved while committing (or not,
depending on how Jiri handles it :-P ).
> drivers/hid/hid-lenovo.c | 16 +++++++++++++---
> 1 file changed, 13 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/hid/hid-lenovo.c b/drivers/hid/hid-lenovo.c
> index 0125e356bd8d..2ba5e8ea66a4 100644
> --- a/drivers/hid/hid-lenovo.c
> +++ b/drivers/hid/hid-lenovo.c
> @@ -184,21 +184,31 @@ static int lenovo_send_cmd_cptkbd(struct hid_device
> *hdev,
> unsigned char byte2, unsigned char byte3)
> {
> int ret;
> - unsigned char buf[] = {0x18, byte2, byte3};
> + unsigned char *buf = NULL;
No need to initialized buf here :)
Cheers,
Benjamin
> +
> + buf = kzalloc(3, GFP_KERNEL);
> + if (!buf)
> + return -ENOMEM;
> +
> + buf[0] = 0x18;
> + buf[1] = byte2;
> + buf[2] = byte3;
>
> switch (hdev->product) {
> case USB_DEVICE_ID_LENOVO_CUSBKBD:
> - ret = hid_hw_raw_request(hdev, 0x13, buf, sizeof(buf),
> + ret = hid_hw_raw_request(hdev, 0x13, buf, 3,
> HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
> break;
> case USB_DEVICE_ID_LENOVO_CBTKBD:
> - ret = hid_hw_output_report(hdev, buf, sizeof(buf));
> + ret = hid_hw_output_report(hdev, buf, 3);
> break;
> default:
> ret = -EINVAL;
> break;
> }
>
> + kfree(buf);
> +
> return ret < 0 ? ret : 0; /* BT returns 0, USB returns sizeof(buf) */
> }
>
> --
> 2.5.5
>
