Hello.
On 08/31/2012 05:56 PM, Forest Bond wrote:
> From: Forest Bond <forest.bond@xxxxxxxxxxxxxxxx>
> Certain eGalax devices expose an interface with class HID and protocol
> None. Some work with usbhid and some work with usbtouchscreen, but
> there is no easy way to differentiate. Sending an eGalax diagnostic
> packet seems to kick them all into using the right protocol for
> usbtouchscreen, so we can continue to bind them all there (as opposed to
> handing some off to usbhid).
> This fixes a regression for devices that were claimed by (and worked
> with) usbhid prior to commit 139ebe8dc80dd74cb2ac9f5603d18fbf5cff049f,
Please also specify that commit's summary ion parens.
> which made usbtouchscreen claim them instead. With this patch they will
> still be claimed by usbtouchscreen, but they will actually report events
> usbtouchscreen can understand. Note that these devices will be limited
> to the usbtouchscreen feature set so e.g. dual touch features are not
> supported.
> I have the distinct pleasure of needing to support devices of both types
> and have tested accordingly.
> Signed-off-by: Forest Bond <forest.bond@xxxxxxxxxxxxxxxx>
> ---
> drivers/input/touchscreen/usbtouchscreen.c | 25 +++++++++++++++++++++++++
> 1 files changed, 25 insertions(+), 0 deletions(-)
> diff --git a/drivers/input/touchscreen/usbtouchscreen.c b/drivers/input/touchscreen/usbtouchscreen.c
> index e32709e..2ce5308 100644
> --- a/drivers/input/touchscreen/usbtouchscreen.c
> +++ b/drivers/input/touchscreen/usbtouchscreen.c
> @@ -304,6 +304,30 @@ static int e2i_read_data(struct usbtouch_usb *dev, unsigned char *pkt)
> #define EGALAX_PKT_TYPE_REPT 0x80
> #define EGALAX_PKT_TYPE_DIAG 0x0A
>
> +static int egalax_init(struct usbtouch_usb *usbtouch)
> +{
> + int ret, i;
> + struct usb_device *udev = interface_to_usbdev(usbtouch->interface);
> +
> + /* An eGalax diagnostic packet kicks the device into using the right
> + * protocol. */
The preferred multi-line comment style is:
/*
* bla
* bla
*/
> + for (i = 0; i < 3; i++) {
> + /* Send a "check active" packet. The response will be read
> + * later and ignored. */
> + ret = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
> + 0,
> + USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
> + 0, 0, "\x0A\x01A", 0,
You probably can't send data from the .const section (as well as off the
stack) -- they can be DMA'ed and there'll be issues with cache consistency on
non-x86 arches. You should allocate the data with kmalloc().
Although, on the second thought, maybe I'm wrong in this case... not really
sure about sending -- receiving (to the .data section) could certainly be harmful...
WBR, Sergei
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