Input: xen-kbdfront - allow better run-time configuration

Commit Message

Oleksandr Andrushchenko April 19, 2018, 1:01 p.m. UTC

On 04/19/2018 03:52 PM, Juergen Gross wrote:
> On 19/04/18 13:44, Oleksandr Andrushchenko wrote:
>> On 04/19/2018 02:25 PM, Juergen Gross wrote:
>>> On 18/04/18 17:04, Oleksandr Andrushchenko wrote:
>>>> From: Oleksandr Andrushchenko <[e-mail]>
>>>>
>>>> It is now only possible to control if multi-touch virtual device
>>>> is created or not (via the corresponding XenStore entries),
>>>> but keyboard and pointer devices are always created.
>>> Why don't you want to go that route for keyboard and mouse, too?
>>> Or does this really make no sense?
>> Well, I would prefer not to touch anything outside Linux and
>> this driver. And these settings seem to be implementation specific.
>> So, this is why introduce Linux module parameters and don't extend
>> the kbdif protocol.
>>>> In some cases this is not desirable. For example, if virtual
>>>> keyboard device is exposed to Android then the latter won't
>>>> automatically show on-screen keyboard as it expects that a
>>>> physical keyboard device can be used for typing.
>>>>
>>>> Make it possible to configure which virtual devices are created
>>>> with module parameters:
>>>>     - no_ptr_dev=1 if no pointer device needs to be created
>>>>     - no_kbd_dev=1 if no keyboard device needs to be created
>>>> Keep old behavior by default.
>>>>
>>>> Signed-off-by: Oleksandr Andrushchenko
>>>> <[e-mail]>
>>>> Suggested-by: Andrii Chepurnyi <[e-mail]>
>>>> Tested-by: Andrii Chepurnyi <[e-mail]>
>>>> ---
>>>>    drivers/input/misc/xen-kbdfront.c | 159 +++++++++++++++++-------------
>>>>    1 file changed, 92 insertions(+), 67 deletions(-)
>>>>
>>>> diff --git a/drivers/input/misc/xen-kbdfront.c
>>>> b/drivers/input/misc/xen-kbdfront.c
>>>> index d91f3b1c5375..a3306aad40b0 100644
>>>> --- a/drivers/input/misc/xen-kbdfront.c
>>>> +++ b/drivers/input/misc/xen-kbdfront.c
>>>> @@ -51,6 +51,16 @@ module_param_array(ptr_size, int, NULL, 0444);
>>>>    MODULE_PARM_DESC(ptr_size,
>>>>        "Pointing device width, height in pixels (default 800,600)");
>>>>    +static unsigned int no_ptr_dev;
>>>> +module_param(no_ptr_dev, uint, 0);
>>> Use type invbool instead?
>> Hm, better bool then? invbool will require parameter name change to
>> something like "with_ptr_dev" which might confuse, e.g.
>> default was to go with pointer device, now we have with_ptr_dev
>> module parameter: do I now need to set it to preserve the old behavior?
>> The answer is no (because of invbool), but you have to dig for it.
>>
>> Will bool work for you?
> As long as the default won't change from today: yes.
Ok, so I'll send v2 with the following changes:


>
> Juergen

--
To unsubscribe from this list: send the line "unsubscribe linux-input" in
the body of a message to [e-mail]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Comments

Jason Andryuk April 19, 2018, 1:10 p.m. UTC | #1

On Thu, Apr 19, 2018 at 9:01 AM, Oleksandr Andrushchenko
<[e-mail]> wrote:
>
> Ok, so I'll send v2 with the following changes:
>
> diff --git a/drivers/input/misc/xen-kbdfront.c
> b/drivers/input/misc/xen-kbdfront.c
> index a3306aad40b0..d8cca212f737 100644
> --- a/drivers/input/misc/xen-kbdfront.c
> +++ b/drivers/input/misc/xen-kbdfront.c
> @@ -51,13 +51,13 @@ module_param_array(ptr_size, int, NULL, 0444);
>  MODULE_PARM_DESC(ptr_size,
>         "Pointing device width, height in pixels (default 800,600)");
>
> -static unsigned int no_ptr_dev;
> -module_param(no_ptr_dev, uint, 0);
> +static bool no_ptr_dev;
> +module_param(no_ptr_dev, bool, 0);
>  MODULE_PARM_DESC(no_ptr_dev,
>         "If set then no virtual pointing device exposed to the guest");
>
> -static unsigned int no_kbd_dev;
> -module_param(no_kbd_dev, uint, 0);
> +static bool no_kbd_dev;
> +module_param(no_kbd_dev, bool, 0);
>  MODULE_PARM_DESC(no_kbd_dev,
>         "If set then no virtual keyboard device exposed to the guest");

I prefer direct logic over inverse logic.  Maybe just use kbd_dev,
default to true, but allow it to be set off?

static bool kbd_dev = true;
module_param(kbd_dev, bool, 0);

Regards,
Jason
--
To unsubscribe from this list: send the line "unsubscribe linux-input" in
the body of a message to [e-mail]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Oleksandr Andrushchenko April 19, 2018, 1:12 p.m. UTC | #2

On 04/19/2018 04:10 PM, Jason Andryuk wrote:
> On Thu, Apr 19, 2018 at 9:01 AM, Oleksandr Andrushchenko
> <[e-mail]> wrote:
>> Ok, so I'll send v2 with the following changes:
>>
>> diff --git a/drivers/input/misc/xen-kbdfront.c
>> b/drivers/input/misc/xen-kbdfront.c
>> index a3306aad40b0..d8cca212f737 100644
>> --- a/drivers/input/misc/xen-kbdfront.c
>> +++ b/drivers/input/misc/xen-kbdfront.c
>> @@ -51,13 +51,13 @@ module_param_array(ptr_size, int, NULL, 0444);
>>   MODULE_PARM_DESC(ptr_size,
>>          "Pointing device width, height in pixels (default 800,600)");
>>
>> -static unsigned int no_ptr_dev;
>> -module_param(no_ptr_dev, uint, 0);
>> +static bool no_ptr_dev;
>> +module_param(no_ptr_dev, bool, 0);
>>   MODULE_PARM_DESC(no_ptr_dev,
>>          "If set then no virtual pointing device exposed to the guest");
>>
>> -static unsigned int no_kbd_dev;
>> -module_param(no_kbd_dev, uint, 0);
>> +static bool no_kbd_dev;
>> +module_param(no_kbd_dev, bool, 0);
>>   MODULE_PARM_DESC(no_kbd_dev,
>>          "If set then no virtual keyboard device exposed to the guest");
> I prefer direct logic over inverse logic.  Maybe just use kbd_dev,
> default to true, but allow it to be set off?
>
> static bool kbd_dev = true;
> module_param(kbd_dev, bool, 0);
I have no preference here, either way works for me
Juergen, what do you think about the above?
> Regards,
> Jason

--
To unsubscribe from this list: send the line "unsubscribe linux-input" in
the body of a message to [e-mail]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Jürgen Groß April 19, 2018, 1:19 p.m. UTC | #3

On 19/04/18 15:12, Oleksandr Andrushchenko wrote:
> On 04/19/2018 04:10 PM, Jason Andryuk wrote:
>> On Thu, Apr 19, 2018 at 9:01 AM, Oleksandr Andrushchenko
>> <[e-mail]> wrote:
>>> Ok, so I'll send v2 with the following changes:
>>>
>>> diff --git a/drivers/input/misc/xen-kbdfront.c
>>> b/drivers/input/misc/xen-kbdfront.c
>>> index a3306aad40b0..d8cca212f737 100644
>>> --- a/drivers/input/misc/xen-kbdfront.c
>>> +++ b/drivers/input/misc/xen-kbdfront.c
>>> @@ -51,13 +51,13 @@ module_param_array(ptr_size, int, NULL, 0444);
>>>   MODULE_PARM_DESC(ptr_size,
>>>          "Pointing device width, height in pixels (default 800,600)");
>>>
>>> -static unsigned int no_ptr_dev;
>>> -module_param(no_ptr_dev, uint, 0);
>>> +static bool no_ptr_dev;
>>> +module_param(no_ptr_dev, bool, 0);
>>>   MODULE_PARM_DESC(no_ptr_dev,
>>>          "If set then no virtual pointing device exposed to the guest");
>>>
>>> -static unsigned int no_kbd_dev;
>>> -module_param(no_kbd_dev, uint, 0);
>>> +static bool no_kbd_dev;
>>> +module_param(no_kbd_dev, bool, 0);
>>>   MODULE_PARM_DESC(no_kbd_dev,
>>>          "If set then no virtual keyboard device exposed to the guest");
>> I prefer direct logic over inverse logic.  Maybe just use kbd_dev,
>> default to true, but allow it to be set off?
>>
>> static bool kbd_dev = true;
>> module_param(kbd_dev, bool, 0);
> I have no preference here, either way works for me
> Juergen, what do you think about the above?

I really have no preference here. What should be taken into account is
that boolean parameters don't need a value, meaning "true" in that case.
This would make no sense for "kbd_dev" as it wouldn't change the
default.

Juergen
--
To unsubscribe from this list: send the line "unsubscribe linux-input" in
the body of a message to [e-mail]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Oleksandr Andrushchenko April 19, 2018, 1:22 p.m. UTC | #4

On 04/19/2018 04:19 PM, Juergen Gross wrote:
> On 19/04/18 15:12, Oleksandr Andrushchenko wrote:
>> On 04/19/2018 04:10 PM, Jason Andryuk wrote:
>>> On Thu, Apr 19, 2018 at 9:01 AM, Oleksandr Andrushchenko
>>> <[e-mail]> wrote:
>>>> Ok, so I'll send v2 with the following changes:
>>>>
>>>> diff --git a/drivers/input/misc/xen-kbdfront.c
>>>> b/drivers/input/misc/xen-kbdfront.c
>>>> index a3306aad40b0..d8cca212f737 100644
>>>> --- a/drivers/input/misc/xen-kbdfront.c
>>>> +++ b/drivers/input/misc/xen-kbdfront.c
>>>> @@ -51,13 +51,13 @@ module_param_array(ptr_size, int, NULL, 0444);
>>>>    MODULE_PARM_DESC(ptr_size,
>>>>           "Pointing device width, height in pixels (default 800,600)");
>>>>
>>>> -static unsigned int no_ptr_dev;
>>>> -module_param(no_ptr_dev, uint, 0);
>>>> +static bool no_ptr_dev;
>>>> +module_param(no_ptr_dev, bool, 0);
>>>>    MODULE_PARM_DESC(no_ptr_dev,
>>>>           "If set then no virtual pointing device exposed to the guest");
>>>>
>>>> -static unsigned int no_kbd_dev;
>>>> -module_param(no_kbd_dev, uint, 0);
>>>> +static bool no_kbd_dev;
>>>> +module_param(no_kbd_dev, bool, 0);
>>>>    MODULE_PARM_DESC(no_kbd_dev,
>>>>           "If set then no virtual keyboard device exposed to the guest");
>>> I prefer direct logic over inverse logic.  Maybe just use kbd_dev,
>>> default to true, but allow it to be set off?
>>>
>>> static bool kbd_dev = true;
>>> module_param(kbd_dev, bool, 0);
>> I have no preference here, either way works for me
>> Juergen, what do you think about the above?
> I really have no preference here. What should be taken into account is
> that boolean parameters don't need a value, meaning "true" in that case.
> This would make no sense for "kbd_dev" as it wouldn't change the
> default.
Then I'll go with the diff above, e.g. boolean no_{kbd|ptr})dev
> Juergen

--
To unsubscribe from this list: send the line "unsubscribe linux-input" in
the body of a message to [e-mail]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Patch

diff --git a/drivers/input/misc/xen-kbdfront.c 
b/drivers/input/misc/xen-kbdfront.c
index a3306aad40b0..d8cca212f737 100644
--- a/drivers/input/misc/xen-kbdfront.c
+++ b/drivers/input/misc/xen-kbdfront.c
@@ -51,13 +51,13 @@  module_param_array(ptr_size, int, NULL, 0444);
  MODULE_PARM_DESC(ptr_size,
         "Pointing device width, height in pixels (default 800,600)");

-static unsigned int no_ptr_dev;
-module_param(no_ptr_dev, uint, 0);
+static bool no_ptr_dev;
+module_param(no_ptr_dev, bool, 0);
  MODULE_PARM_DESC(no_ptr_dev,
         "If set then no virtual pointing device exposed to the guest");

-static unsigned int no_kbd_dev;
-module_param(no_kbd_dev, uint, 0);
+static bool no_kbd_dev;
+module_param(no_kbd_dev, bool, 0);
  MODULE_PARM_DESC(no_kbd_dev,
         "If set then no virtual keyboard device exposed to the guest");