On Tue, Apr 24, 2012 at 01:46:15PM -0700, Ping Cheng wrote:
> On Fri, Apr 20, 2012 at 10:56 PM, Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx
> > wrote:
>
> > Hi Chris, Ping,
> >
> > On Sun, Apr 15, 2012 at 05:50:23PM -0500, chris@xxxxxxxxxxxxxx wrote:
> > > From: Ping Cheng <pinglinux@xxxxxxxxx>
> > >
> > > From the HID usage table when it is supported.
> > >
> > > Tested-by: Jason Gerecke <killertofu@xxxxxxxxx>
> > > Signed-off-by: Chris Bagwell <chris@xxxxxxxxxxxxxx>
> > > Signed-off-by: Ping Cheng <pingc@xxxxxxxxx>
> > > ---
> > > drivers/input/tablet/wacom_sys.c | 22 +++++++++++++-
> > > drivers/input/tablet/wacom_wac.c | 59
> > +++++++++++++++++++++++---------------
> > > drivers/input/tablet/wacom_wac.h | 1 +
> > > 3 files changed, 58 insertions(+), 24 deletions(-)
> > >
> > > diff --git a/drivers/input/tablet/wacom_sys.c
> > b/drivers/input/tablet/wacom_sys.c
> > > index 1c874ad..469f6ce 100644
> > > --- a/drivers/input/tablet/wacom_sys.c
> > > +++ b/drivers/input/tablet/wacom_sys.c
> > > @@ -28,6 +28,7 @@
> > > #define HID_USAGE_Y_TILT 0x3e
> > > #define HID_USAGE_FINGER 0x22
> > > #define HID_USAGE_STYLUS 0x20
> > > +#define HID_USAGE_CONTACTMAX 0x55
> > > #define HID_COLLECTION 0xa1
> > > #define HID_COLLECTION_LOGICAL 0x02
> > > #define HID_COLLECTION_END 0xc0
> > > @@ -201,6 +202,20 @@ static int wacom_parse_logical_collection(unsigned
> > char *report,
> > > return length;
> > > }
> > >
> > > +static void wacom_retrieve_report_data(struct usb_interface *intf,
> > > + struct wacom_features *features)
> > > +{
> > > + int result = 0;
> > > + unsigned char rep_data[2];
> >
> > You can't use on-stack buffers with USB. I see we allocating memory
> > elsewhere but I wonder if we should simply piggyback on wacom_wac->data
> > in all these interrogation methods.
> >
>
> When you say piggyback on wacom_wac->data, I guess you meant using the same
> wacom_wac->data instead of creating a new entry for the others. However,
> wacom_wac->data has a sizeof(struct wacom_usbdev_data). The existing
> kzalloc requests in wacom_sys.c range from 2 to 259, assuming we do not
> consider those kzallocs that handle variable sizes, such as
> hid_desc->wDescriptorLength.
>
> What size would be reasonable for the new data? I feel we need to introduce
> a new entry in wacom_wac if we want to unify the kzalloc request a bit.
Hmm, maybe piggybacking was not such a good idea. We want to keep
buffers used by leds separate since these operations can appen
simultaneously and since we also have to deal with variable length of
hid descriptors I think we should just kmalloc memory in
wacom_retrieve_report_data() and be done with it.
--
Dmitry
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