linux-kernel - Re: [PATCH v2 2/2] xen,input: repair xen-kbdfront resolution setting via xenstore

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Message-ID: <7ce36d3c-5921-53fa-12fb-3940dc5023de@gmail.com>
Date:   Tue, 11 Apr 2017 12:00:34 +0300
From:   Oleksandr Andrushchenko <andr2000@...il.com>
To:     Juergen Gross <jgross@...e.com>, linux-kernel@...r.kernel.org,
        xen-devel@...ts.xenproject.org, linux-input@...r.kernel.org
Cc:     boris.ostrovsky@...cle.com, dmitry.torokhov@...il.com
Subject: Re: [PATCH v2 2/2] xen,input: repair xen-kbdfront resolution setting
 via xenstore

Hi, Juergen,

could you please make one more patch in the series:

the code that you fix in this patch is ok, but most

of the functionality of the xenkbd_set_connected

is still useless: feature-abs-pointer/request-abs-pointer

negotiation has only meaning at probe time, when we are

configuring input device:

     if (abs) {
         __set_bit(EV_ABS, ptr->evbit);
         input_set_abs_params(ptr, ABS_X, 0, XENFB_WIDTH, 0, 0);
         input_set_abs_params(ptr, ABS_Y, 0, XENFB_HEIGHT, 0, 0);
     } else {
         input_set_capability(ptr, EV_REL, REL_X);
         input_set_capability(ptr, EV_REL, REL_Y);
     }
Once the input device is configured and registered (probe done)

we do not touch/re-configure that input device anymore,

regardless of the setting negotiation at xenkbd_set_connected

time. Thus, this code is not needed and can be cleaned out.

What your patch actually fixes is the fact that

"xenbus_switch_state(dev, XenbusStateConnected);" was not called,

so this is the only line needed.

Thank you,

Oleksandr


On 04/11/2017 11:50 AM, Juergen Gross wrote:
> Setting the pointing device resolution via Xenstore isn't working
> reliably: in case XenbusStateInitWait has been missed the resolution
> settings won't be read. Correct this.
>
> Signed-off-by: Juergen Gross <jgross@...e.com>
> Reviewed-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@...m.com>
> ---
>   drivers/input/misc/xen-kbdfront.c | 32 ++++++++++++++++++++------------
>   1 file changed, 20 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/input/misc/xen-kbdfront.c b/drivers/input/misc/xen-kbdfront.c
> index 90e7981a7768..fc28f59dfa93 100644
> --- a/drivers/input/misc/xen-kbdfront.c
> +++ b/drivers/input/misc/xen-kbdfront.c
> @@ -312,11 +312,27 @@ static void xenkbd_disconnect_backend(struct xenkbd_info *info)
>   	info->gref = -1;
>   }
>   
> +static void xenkbd_set_connected(struct xenbus_device *dev)
> +{
> +	struct xenkbd_info *info = dev_get_drvdata(&dev->dev);
> +	int ret;
> +
> +	if (xenbus_read_unsigned(info->xbdev->otherend,
> +				 "feature-abs-pointer", 0)) {
> +		ret = xenbus_write(XBT_NIL, info->xbdev->nodename,
> +				   "request-abs-pointer", "1");
> +		if (ret)
> +			pr_warn("xenkbd: can't request abs-pointer");
> +	}
> +
> +	xenbus_switch_state(dev, XenbusStateConnected);
> +}
> +
>   static void xenkbd_backend_changed(struct xenbus_device *dev,
>   				   enum xenbus_state backend_state)
>   {
>   	struct xenkbd_info *info = dev_get_drvdata(&dev->dev);
> -	int ret, val;
> +	int val;
>   
>   	switch (backend_state) {
>   	case XenbusStateInitialising:
> @@ -327,16 +343,7 @@ static void xenkbd_backend_changed(struct xenbus_device *dev,
>   		break;
>   
>   	case XenbusStateInitWait:
> -InitWait:
> -		if (xenbus_read_unsigned(info->xbdev->otherend,
> -					 "feature-abs-pointer", 0)) {
> -			ret = xenbus_write(XBT_NIL, info->xbdev->nodename,
> -					   "request-abs-pointer", "1");
> -			if (ret)
> -				pr_warning("xenkbd: can't request abs-pointer");
> -		}
> -
> -		xenbus_switch_state(dev, XenbusStateConnected);
> +		xenkbd_set_connected(dev);
>   		break;
>   
>   	case XenbusStateConnected:
> @@ -346,7 +353,8 @@ static void xenkbd_backend_changed(struct xenbus_device *dev,
>   		 * get Connected twice here.
>   		 */
>   		if (dev->state != XenbusStateConnected)
> -			goto InitWait; /* no InitWait seen yet, fudge it */
> +			/* No InitWait seen yet, fudge it. */
> +			xenkbd_set_connected(dev);
>   
>   		/* Set input abs params to match backend screen res */
>   		if (xenbus_scanf(XBT_NIL, info->xbdev->otherend,