From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753648AbdDJOSZ (ORCPT ); Mon, 10 Apr 2017 10:18:25 -0400 Received: from mail-wm0-f65.google.com ([74.125.82.65]:36280 "EHLO mail-wm0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752760AbdDJOSX (ORCPT ); Mon, 10 Apr 2017 10:18:23 -0400 Subject: Re: [Xen-devel] [PATCH 1/2] xen, input: add xen-kbdfront module parameter for setting resolution To: Juergen Gross , linux-kernel@vger.kernel.org, xen-devel@lists.xenproject.org, linux-input@vger.kernel.org References: <20170321171905.31584-1-jgross@suse.com> <20170321171905.31584-2-jgross@suse.com> <44a8ef04-53eb-df79-868e-96cc12302a78@suse.com> <3441af57-3609-6268-c3f8-a88147553892@suse.com> Cc: dmitry.torokhov@gmail.com From: Oleksandr Andrushchenko Message-ID: <0d7df625-27a1-0c1e-49f3-e1d44c09a787@gmail.com> Date: Mon, 10 Apr 2017 17:18:20 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.8.0 MIME-Version: 1.0 In-Reply-To: <3441af57-3609-6268-c3f8-a88147553892@suse.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/10/2017 05:11 PM, Juergen Gross wrote: > On 10/04/17 16:00, Oleksandr Andrushchenko wrote: >> >> On 04/10/2017 04:50 PM, Juergen Gross wrote: >>> On 10/04/17 15:44, Oleksandr Andrushchenko wrote: >>>> Hi, Juergen! >>>> >>>> On 03/21/2017 07:19 PM, Juergen Gross wrote: >>>>> Add a parameter for setting the resolution of xen-kbdfront in order to >>>>> be able to cope with a (virtual) frame buffer of arbitrary resolution. >>>>> >>>>> Signed-off-by: Juergen Gross >>>>> --- >>>>> drivers/input/misc/xen-kbdfront.c | 10 ++++++++-- >>>>> 1 file changed, 8 insertions(+), 2 deletions(-) >>>>> >>>>> diff --git a/drivers/input/misc/xen-kbdfront.c >>>>> b/drivers/input/misc/xen-kbdfront.c >>>>> index 3900875..2df5678 100644 >>>>> --- a/drivers/input/misc/xen-kbdfront.c >>>>> +++ b/drivers/input/misc/xen-kbdfront.c >>>>> @@ -41,6 +41,12 @@ struct xenkbd_info { >>>>> char phys[32]; >>>>> }; >>>>> +enum { KPARAM_WIDTH, KPARAM_HEIGHT, KPARAM_CNT }; >>>>> +static int size[KPARAM_CNT] = { XENFB_WIDTH, XENFB_HEIGHT }; >>>>> +module_param_array(size, int, NULL, 0444); >>>> is this by intention that you use 0444 here? >>>> It means read-only, thus one cannot change these, >>>> so what is the point of the module parameters then? >>> You can see the settings in sysfs. >> this is good so we can see actual width/height >> used by the pv driver >>> The values are settable via boot parameter. >> but then, if one has other values set in XenStore, >> these will/may be overridden, making it inconsistent, >> e.g. values loaded at start as module parameters >> (*size* array) is not going to be updated on >> XenbusStateInitWait/XenbusStateConnected. So, we'll >> end up with wrong parameters shown via sysfs >> one more question is why do we need module parameters >> if the same can be read from XenStore? > Because up to now nobody is setting the Xenstore values. This is > something I'm planning to do for Xen 4.10. ah, good to know. btw, if you are about to add width/height for the pointer device will you also add the same for multi-touch? > Up to then we need a > workaround. > > But you are right: The module parameters should be updated with > the values read from Xenstore. > > > Juergen