diff options
| author | Johan Hovold <johan@kernel.org> | 2021-01-04 15:53:02 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-01-04 16:51:35 +0100 |
| commit | 020a1f453449294926ca548d8d5ca970926e8dfd (patch) | |
| tree | 9d117299d9e3944d7efbc83526a4c21581b93833 /drivers/usb/class/usblp.c | |
| parent | c318840fb2a42ce25febc95c4c19357acf1ae5ca (diff) | |
USB: usblp: fix DMA to stack
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>
Link: https://lore.kernel.org/r/20210104145302.2087-1-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/class/usblp.c')
| -rw-r--r-- | drivers/usb/class/usblp.c | 21 |
1 files 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; +} /* * See the description for usblp_select_alts() below for the usage |