On Mon, Jan 04, 2021 at 03:53:02PM +0100, Johan Hovold wrote:
Stack-allocated buffers cannot be used for DMA (on all architectures).
Replace the HP-channel macro with a helper function that allocates a dedicated transfer buffer so that it can continue to be used with arguments from the stack.
Note that the buffer is cleared on allocation as usblp_ctrl_msg() returns success also on short transfers (the buffer is only used for debugging).
Cc: stable@vger.kernel.org Signed-off-by: Johan Hovold johan@kernel.org
drivers/usb/class/usblp.c | 21 +++++++++++++++++++-- 1 file changed, 19 insertions(+), 2 deletions(-)
diff --git a/drivers/usb/class/usblp.c b/drivers/usb/class/usblp.c index 67cbd42421be..134dc2005ce9 100644 --- a/drivers/usb/class/usblp.c +++ b/drivers/usb/class/usblp.c @@ -274,8 +274,25 @@ static int usblp_ctrl_msg(struct usblp *usblp, int request, int type, int dir, i #define usblp_reset(usblp)\ usblp_ctrl_msg(usblp, USBLP_REQ_RESET, USB_TYPE_CLASS, USB_DIR_OUT, USB_RECIP_OTHER, 0, NULL, 0) -#define usblp_hp_channel_change_request(usblp, channel, buffer) \
- usblp_ctrl_msg(usblp, USBLP_REQ_HP_CHANNEL_CHANGE_REQUEST, USB_TYPE_VENDOR, USB_DIR_IN, USB_RECIP_INTERFACE, channel, buffer, 1)
+static int usblp_hp_channel_change_request(struct usblp *usblp, int channel, u8 *new_channel) +{
- u8 *buf;
- int ret;
- buf = kzalloc(1, GFP_KERNEL);
- if (!buf)
return -ENOMEM;
- ret = usblp_ctrl_msg(usblp, USBLP_REQ_HP_CHANNEL_CHANGE_REQUEST,
USB_TYPE_VENDOR, USB_DIR_IN, USB_RECIP_INTERFACE,
channel, buf, 1);
- if (ret == 0)
*new_channel = buf[0];
- kfree(buf);
- return ret;
+}
Wow, no one uses this driver anymore it seems, this should have triggered a runtime warning on newer kernels :(
Thanks for this, will queue it up soon.
greg k-h