Re: [Xen-devel] [PATCH v2] xen, input: try to read screen resolution for xen-kbdfront

[Dmitry Torokhov]

On January 27, 2017 12:31:19 AM PST, Juergen Gross <jgross@xxxxxxxx> wrote:
>On 27/01/17 09:26, Oleksandr Andrushchenko wrote:
>> On 01/27/2017 10:14 AM, Juergen Gross wrote:
>>> On 27/01/17 08:53, Oleksandr Andrushchenko wrote:
>>>> On 01/27/2017 09:46 AM, Juergen Gross wrote:
>>>>> On 27/01/17 08:21, Oleksandr Andrushchenko wrote:
>>>>>> On 01/27/2017 09:12 AM, Juergen Gross wrote:
>>>>>>> Instead of using the default resolution of 800*600 for the
>pointing
>>>>>>> device of xen-kbdfront try to read the resolution of the
>(virtual)
>>>>>>> framebuffer device. Use the default as fallback only.
>>>>>>>
>>>>>>> Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
>>>>>>> ---
>>>>>>> V2: get framebuffer resolution only if CONFIG_FB (Dmitry
>Torokhov)
>>>>>>> ---
>>>>>>>     drivers/input/misc/xen-kbdfront.c | 15 ++++++++++++---
>>>>>>>     1 file changed, 12 insertions(+), 3 deletions(-)
>>>>>>>
>>>>>>> diff --git a/drivers/input/misc/xen-kbdfront.c
>>>>>>> b/drivers/input/misc/xen-kbdfront.c
>>>>>>> index 3900875..3aae9b4 100644
>>>>>>> --- a/drivers/input/misc/xen-kbdfront.c
>>>>>>> +++ b/drivers/input/misc/xen-kbdfront.c
>>>>>>> @@ -16,6 +16,7 @@
>>>>>>>     #include <linux/kernel.h>
>>>>>>>     #include <linux/errno.h>
>>>>>>>     #include <linux/module.h>
>>>>>>> +#include <linux/fb.h>
>>>>>>>     #include <linux/input.h>
>>>>>>>     #include <linux/slab.h>
>>>>>>>     @@ -108,7 +109,7 @@ static irqreturn_t input_handler(int rq,
>void
>>>>>>> *dev_id)
>>>>>>>     static int xenkbd_probe(struct xenbus_device *dev,
>>>>>>>                       const struct xenbus_device_id *id)
>>>>>>>     {
>>>>>>> -    int ret, i;
>>>>>>> +    int ret, i, width, height;
>>>>>>>         unsigned int abs;
>>>>>>>         struct xenkbd_info *info;
>>>>>>>         struct input_dev *kbd, *ptr;
>>>>>>> @@ -173,9 +174,17 @@ static int xenkbd_probe(struct
>xenbus_device
>>>>>>> *dev,
>>>>>>>         ptr->id.product = 0xfffe;
>>>>>>>           if (abs) {
>>>>>>> +        width = XENFB_WIDTH;
>>>>>>> +        height = XENFB_HEIGHT;
>>>>>>> +#ifdef CONFIG_FB
>>>>>>> +        if (registered_fb[0]) {
>>>>>> This still will not help if FB gets registered after kbd+ptr
>>>>> Hmm, so you think I should add a call to fb_register_client() to
>get
>>>>> events for new registered framebuffer devices?
>>>> yes, but also pay attention to CONFIG_FB_NOTIFY: you may still
>>>> end up w/o notification.
>>> Okay, that's not worse than today.
>> agree
>>>>> This would probably work. I'll have a try.
>>>>>
>>>>>
>>>>> Thanks,
>>>>>
>>>>> Juergen
>>>> My bigger concern here is that we try to tie keyboard and pointer
>device
>>>> to the framebuffer. IMO, these are independent parts of the system
>and
>>>> the relation
>>>> depends on the use-case. One can have graphics enabled w/o
>framebuffer
>>>> at all, e.g.
>>>> DRM/KMS + OpenGLES + Weston + kbd + ptr...
>>> Again: that's a use case which will work as today. The current
>defaults
>>> are being used.
>>>
>>> The question is whether we should add a module parameter switching
>off
>>> the automatic adaption of the resolution as there might be use cases
>>> where we don't want this feature.
>> I think for those who doesn't want this resolution there is
>> still a possibility to change it on backend's XenbusStateConnected
>> So, no need for module parameter, IMO
>
>Fine.
>
>I'll send V3 soon.

How about you do the axis adjustment from userspace (udev rule), and leave kernel as is?


Thanks.

-- 
Dmitry