Re: [PATCH v3 2/2] Input: xen-kbdfront - allow better run-time configuration
From: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Date: 2018-05-16 17:15:35
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Hi Oleksandr, On Mon, May 14, 2018 at 05:40:29PM +0300, Oleksandr Andrushchenko wrote:
quoted hunk ↗ jump to hunk
@@ -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; ? Thanks. -- Dmitry