On 05/16/2018 08:15 PM, Dmitry Torokhov wrote:
Hi Oleksandr,
On Mon, May 14, 2018 at 05:40:29PM +0300, Oleksandr Andrushchenko wrote:
@@ -211,93 +220,114 @@ static int xenkbd_probe(struct xenbus_device *dev,
if (!info->page)
goto error_nomem;
- /* Set input abs params to match backend screen res */
- abs = xenbus_read_unsigned(dev->otherend,
- XENKBD_FIELD_FEAT_ABS_POINTER, 0);
- ptr_size[KPARAM_X] = xenbus_read_unsigned(dev->otherend,
- XENKBD_FIELD_WIDTH,
- ptr_size[KPARAM_X]);
- ptr_size[KPARAM_Y] = xenbus_read_unsigned(dev->otherend,
- XENKBD_FIELD_HEIGHT,
- ptr_size[KPARAM_Y]);
- if (abs) {
- ret = xenbus_write(XBT_NIL, dev->nodename,
- XENKBD_FIELD_REQ_ABS_POINTER, "1");
- if (ret) {
- pr_warn("xenkbd: can't request abs-pointer\n");
- abs = 0;
- }
- }
+ /*
+ * The below are reverse logic, e.g. if the feature is set, then
+ * do not expose the corresponding virtual device.
+ */
+ with_kbd = !xenbus_read_unsigned(dev->nodename,
+ XENKBD_FIELD_FEAT_DSBL_KEYBRD, 0);
- touch = xenbus_read_unsigned(dev->nodename,
- XENKBD_FIELD_FEAT_MTOUCH, 0);
- if (touch) {
+ with_ptr = !xenbus_read_unsigned(dev->nodename,
+ XENKBD_FIELD_FEAT_DSBL_POINTER, 0);
+
+ /* Direct logic: if set, then create multi-touch device. */
+ with_mtouch = xenbus_read_unsigned(dev->nodename,
+ XENKBD_FIELD_FEAT_MTOUCH, 0);
+ if (with_mtouch) {
ret = xenbus_write(XBT_NIL, dev->nodename,
XENKBD_FIELD_REQ_MTOUCH, "1");
if (ret) {
pr_warn("xenkbd: can't request multi-touch");
- touch = 0;
+ with_mtouch = 0;
}
}
Does it make sense to still end up calling xenkbd_connect_backend() when
all interfaces (keyboard, pointer, and multitouch) are disabled? Should
we do:
if (!(with_kbd || || with_ptr || with_mtouch))
return -ENXIO;
?
It does make sense. Then we probably need to move all xenbus_read_unsigned
calls to the very beginning of the .probe, so no memory allocations are made
which will be useless if we return -ENXIO, e.g. something like
static int xenkbd_probe(struct xenbus_device *dev,
const struct xenbus_device_id *id)
{
int ret, i;
bool with_mtouch, with_kbd, with_ptr;
struct xenkbd_info *info;
struct input_dev *kbd, *ptr, *mtouch;
<read with_mtouch, with_kbd, with_ptr here>
if (!(with_kbd | with_ptr | with_mtouch))
return -ENXIO;
Does the above looks ok?
Thanks.
Thank you,
Oleksandr
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