Messages in this thread Patch in this message | | | Date | Tue, 11 Oct 2016 23:19:13 -0300 | From | Mauro Carvalho Chehab <> | Subject | Re: [PATCH v2 28/31] cpia2_usb: don't use stack for DMA |
| |
Em Tue, 11 Oct 2016 22:56:06 +0000 Kosuke Tatsukawa <tatsu@ab.jp.nec.com> escreveu:
> Hi, > > > The USB control messages require DMA to work. We cannot pass > > a stack-allocated buffer, as it is not warranted that the > > stack would be into a DMA enabled area. > > > > Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com> > > Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> > > --- > > drivers/media/usb/cpia2/cpia2_usb.c | 32 +++++++++++++++++++++++++++++--- > > 1 file changed, 29 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/media/usb/cpia2/cpia2_usb.c b/drivers/media/usb/cpia2/cpia2_usb.c > > index 13620cdf0599..417d683b237d 100644 > > --- a/drivers/media/usb/cpia2/cpia2_usb.c > > +++ b/drivers/media/usb/cpia2/cpia2_usb.c > > @@ -545,10 +545,19 @@ static void free_sbufs(struct camera_data *cam) > > static int write_packet(struct usb_device *udev, > > u8 request, u8 * registers, u16 start, size_t size) > > { > > + unsigned char *buf; > > + int ret; > > + > > if (!registers || size <= 0) > > return -EINVAL; > > > > - return usb_control_msg(udev, > > + buf = kmalloc(size, GFP_KERNEL); > > + if (!buf) > > + return -ENOMEM; > > + > > + memcpy(buf, registers, size); > > + > > + ret = usb_control_msg(udev, > > usb_sndctrlpipe(udev, 0), > > request, > > USB_TYPE_VENDOR | USB_RECIP_DEVICE, > > @@ -557,6 +566,9 @@ static int write_packet(struct usb_device *udev, > > registers, /* buffer */ > ========= > > I think you also want to change the argument to usb_control_msg() from > "registers" to "buf" in write_packet().
True!
Thanks for pointing it! Just sent a version of the patch with this fixed.
Regards, Mauro
| |