Hi Insu, On 15/10/15 19:12, Insu Yun wrote: > > > On Thu, Oct 15, 2015 at 12:40 PM, David Vrabel <david.vrabel@xxxxxxxxxx > <mailto:david.vrabel@xxxxxxxxxx>> wrote: > > On 15/10/15 17:25, Insu Yun wrote: > > Internally, xenbus_printf uses memory allocation, so it can be failed in > > memory pressure.Therefore, xenbus_printf's return should be checked > > and properly handled. > [...] > > --- a/drivers/input/misc/xen-kbdfront.c > > +++ b/drivers/input/misc/xen-kbdfront.c > > @@ -129,8 +129,11 @@ static int xenkbd_probe(struct xenbus_device *dev, > > > > if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-abs-pointer", "%d", &abs) < 0) > > abs = 0; > > - if (abs) > > - xenbus_printf(XBT_NIL, dev->nodename, "request-abs-pointer", "1"); > > + if (abs) { > > + ret = xenbus_printf(XBT_NIL, dev->nodename, "request-abs-pointer", "1"); > > + if (ret) > > > + pr_warning("xenkbd: can't request abs-pointer"); > > > This error handling is from other code . > I am not sure that it is right error handling. > > > > I think you want abs = 0 here or input device will be configured as > absolute but the backend will supply relative coordinates. > > > I cannot understand If the frontend is not able to write the node "request-abs-pointer" in the xenstore, the backend will always supply relative coordinates. Although, as abs = 1, the frontend will be configured to handle absolute coordinate. So the backend and frontend won't be able to understand each other. So you have to set abs to 0 if xebus_printf fails. Regards, -- Julien Grall -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
