[PATCH RESEND v2] virtio-input: add multi-touch support

[PATCH RESEND v2] virtio-input: add multi-touch support

[Vasyl Vavrychuk]

From: Mathias Crombez <mathias.crombez@faurecia.com>

Without multi-touch slots allocated, ABS_MT_SLOT events will be lost by
input_handle_abs_event.

Signed-off-by: Mathias Crombez <mathias.crombez@faurecia.com>
Signed-off-by: Vasyl Vavrychuk <vasyl.vavrychuk@opensynergy.com>
Tested-by: Vasyl Vavrychuk <vasyl.vavrychuk@opensynergy.com>
---
v2: fix patch corrupted by corporate email server

 drivers/virtio/Kconfig        | 11 +++++++++++
 drivers/virtio/virtio_input.c |  8 ++++++++
 2 files changed, 19 insertions(+)

diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig
index 7b41130d3f35..2cfd5b01d96d 100644
--- a/drivers/virtio/Kconfig
+++ b/drivers/virtio/Kconfig
@@ -111,6 +111,17 @@ config VIRTIO_INPUT
 
 	 If unsure, say M.
 
+config VIRTIO_INPUT_MULTITOUCH_SLOTS
+	depends on VIRTIO_INPUT
+	int "Number of multitouch slots"
+	range 0 64
+	default 10
+	help
+	 Define the number of multitouch slots used. Default to 10.
+	 This parameter is unused if there is no multitouch capability.
+
+	 0 will disable the feature.
+
 config VIRTIO_MMIO
 	tristate "Platform bus driver for memory mapped virtio devices"
 	depends on HAS_IOMEM && HAS_DMA
diff --git a/drivers/virtio/virtio_input.c b/drivers/virtio/virtio_input.c
index f1f6208edcf5..13f3d90e6c30 100644
--- a/drivers/virtio/virtio_input.c
+++ b/drivers/virtio/virtio_input.c
@@ -7,6 +7,7 @@
 
 #include <uapi/linux/virtio_ids.h>
 #include <uapi/linux/virtio_input.h>
+#include <linux/input/mt.h>
 
 struct virtio_input {
 	struct virtio_device       *vdev;
@@ -205,6 +206,7 @@ static int virtinput_probe(struct virtio_device *vdev)
 	unsigned long flags;
 	size_t size;
 	int abs, err;
+	bool is_mt = false;
 
 	if (!virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
 		return -ENODEV;
@@ -287,9 +289,15 @@ static int virtinput_probe(struct virtio_device *vdev)
 		for (abs = 0; abs < ABS_CNT; abs++) {
 			if (!test_bit(abs, vi->idev->absbit))
 				continue;
+			if (input_is_mt_value(abs))
+				is_mt = true;
 			virtinput_cfg_abs(vi, abs);
 		}
 	}
+	if (is_mt)
+		input_mt_init_slots(vi->idev,
+				    CONFIG_VIRTIO_INPUT_MULTITOUCH_SLOTS,
+				    INPUT_MT_DIRECT);
 
 	virtio_device_ready(vdev);
 	vi->ready = true;
-- 
2.23.0

Re: [PATCH RESEND v2] virtio-input: add multi-touch support

[Dmitry Torokhov]

Hi Vasyl,

On Tue, Dec 08, 2020 at 11:01:50PM +0200, Vasyl Vavrychuk wrote:
> From: Mathias Crombez <mathias.crombez@faurecia.com>
> 
> Without multi-touch slots allocated, ABS_MT_SLOT events will be lost by
> input_handle_abs_event.
> 
> Signed-off-by: Mathias Crombez <mathias.crombez@faurecia.com>
> Signed-off-by: Vasyl Vavrychuk <vasyl.vavrychuk@opensynergy.com>
> Tested-by: Vasyl Vavrychuk <vasyl.vavrychuk@opensynergy.com>
> ---
> v2: fix patch corrupted by corporate email server
> 
>  drivers/virtio/Kconfig        | 11 +++++++++++
>  drivers/virtio/virtio_input.c |  8 ++++++++
>  2 files changed, 19 insertions(+)
> 
> diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig
> index 7b41130d3f35..2cfd5b01d96d 100644
> --- a/drivers/virtio/Kconfig
> +++ b/drivers/virtio/Kconfig
> @@ -111,6 +111,17 @@ config VIRTIO_INPUT
>  
>  	 If unsure, say M.
>  
> +config VIRTIO_INPUT_MULTITOUCH_SLOTS
> +	depends on VIRTIO_INPUT
> +	int "Number of multitouch slots"
> +	range 0 64
> +	default 10
> +	help
> +	 Define the number of multitouch slots used. Default to 10.
> +	 This parameter is unused if there is no multitouch capability.

I believe the number of slots should be communicated to the guest by
the host, similarly to how the rest of input device capabilities is
transferred, instead of having static compile-time option.

> +
> +	 0 will disable the feature.
> +
>  config VIRTIO_MMIO
>  	tristate "Platform bus driver for memory mapped virtio devices"
>  	depends on HAS_IOMEM && HAS_DMA
> diff --git a/drivers/virtio/virtio_input.c b/drivers/virtio/virtio_input.c
> index f1f6208edcf5..13f3d90e6c30 100644
> --- a/drivers/virtio/virtio_input.c
> +++ b/drivers/virtio/virtio_input.c
> @@ -7,6 +7,7 @@
>  
>  #include <uapi/linux/virtio_ids.h>
>  #include <uapi/linux/virtio_input.h>
> +#include <linux/input/mt.h>
>  
>  struct virtio_input {
>  	struct virtio_device       *vdev;
> @@ -205,6 +206,7 @@ static int virtinput_probe(struct virtio_device *vdev)
>  	unsigned long flags;
>  	size_t size;
>  	int abs, err;
> +	bool is_mt = false;
>  
>  	if (!virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
>  		return -ENODEV;
> @@ -287,9 +289,15 @@ static int virtinput_probe(struct virtio_device *vdev)
>  		for (abs = 0; abs < ABS_CNT; abs++) {
>  			if (!test_bit(abs, vi->idev->absbit))
>  				continue;
> +			if (input_is_mt_value(abs))
> +				is_mt = true;
>  			virtinput_cfg_abs(vi, abs);
>  		}
>  	}
> +	if (is_mt)
> +		input_mt_init_slots(vi->idev,
> +				    CONFIG_VIRTIO_INPUT_MULTITOUCH_SLOTS,
> +				    INPUT_MT_DIRECT);

Here errors need to be handled.

>  
>  	virtio_device_ready(vdev);
>  	vi->ready = true;
> -- 
> 2.23.0
> 

Thanks.

-- 
Dmitry

Re: [PATCH RESEND v2] virtio-input: add multi-touch support

[Greg KH]

On Tue, Dec 08, 2020 at 11:01:50PM +0200, Vasyl Vavrychuk wrote:
> From: Mathias Crombez <mathias.crombez@faurecia.com>
> 
> Without multi-touch slots allocated, ABS_MT_SLOT events will be lost by
> input_handle_abs_event.
> 
> Signed-off-by: Mathias Crombez <mathias.crombez@faurecia.com>
> Signed-off-by: Vasyl Vavrychuk <vasyl.vavrychuk@opensynergy.com>
> Tested-by: Vasyl Vavrychuk <vasyl.vavrychuk@opensynergy.com>
> ---
> v2: fix patch corrupted by corporate email server
> 
>  drivers/virtio/Kconfig        | 11 +++++++++++
>  drivers/virtio/virtio_input.c |  8 ++++++++
>  2 files changed, 19 insertions(+)

<formletter>

This is not the correct way to submit patches for inclusion in the
stable kernel tree.  Please read:
    https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html
for how to do this properly.

</formletter>

Re: [PATCH RESEND v2] virtio-input: add multi-touch support

[Michael S. Tsirkin]

On Tue, Dec 08, 2020 at 11:01:50PM +0200, Vasyl Vavrychuk wrote:
> From: Mathias Crombez <mathias.crombez@faurecia.com>
> Cc: stable@vger.kernel.org

I don't believe this is appropriate for stable, looks like
a new feature to me.


> 
> Without multi-touch slots allocated, ABS_MT_SLOT events will be lost by
> input_handle_abs_event.
> 
> Signed-off-by: Mathias Crombez <mathias.crombez@faurecia.com>
> Signed-off-by: Vasyl Vavrychuk <vasyl.vavrychuk@opensynergy.com>
> Tested-by: Vasyl Vavrychuk <vasyl.vavrychuk@opensynergy.com>
> ---
> v2: fix patch corrupted by corporate email server
> 
>  drivers/virtio/Kconfig        | 11 +++++++++++
>  drivers/virtio/virtio_input.c |  8 ++++++++
>  2 files changed, 19 insertions(+)
> 
> diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig
> index 7b41130d3f35..2cfd5b01d96d 100644
> --- a/drivers/virtio/Kconfig
> +++ b/drivers/virtio/Kconfig
> @@ -111,6 +111,17 @@ config VIRTIO_INPUT
>  
>  	 If unsure, say M.
>  
> +config VIRTIO_INPUT_MULTITOUCH_SLOTS
> +	depends on VIRTIO_INPUT
> +	int "Number of multitouch slots"
> +	range 0 64
> +	default 10
> +	help
> +	 Define the number of multitouch slots used. Default to 10.
> +	 This parameter is unused if there is no multitouch capability.
> +
> +	 0 will disable the feature.
> +

Most people won't be using this config so the defaults matter. So why 10? 10 fingers?

And where does 64 come from?


>  config VIRTIO_MMIO
>  	tristate "Platform bus driver for memory mapped virtio devices"
>  	depends on HAS_IOMEM && HAS_DMA
> diff --git a/drivers/virtio/virtio_input.c b/drivers/virtio/virtio_input.c
> index f1f6208edcf5..13f3d90e6c30 100644
> --- a/drivers/virtio/virtio_input.c
> +++ b/drivers/virtio/virtio_input.c
> @@ -7,6 +7,7 @@
>  
>  #include <uapi/linux/virtio_ids.h>
>  #include <uapi/linux/virtio_input.h>
> +#include <linux/input/mt.h>
>  
>  struct virtio_input {
>  	struct virtio_device       *vdev;
> @@ -205,6 +206,7 @@ static int virtinput_probe(struct virtio_device *vdev)
>  	unsigned long flags;
>  	size_t size;
>  	int abs, err;
> +	bool is_mt = false;
>  
>  	if (!virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
>  		return -ENODEV;
> @@ -287,9 +289,15 @@ static int virtinput_probe(struct virtio_device *vdev)
>  		for (abs = 0; abs < ABS_CNT; abs++) {
>  			if (!test_bit(abs, vi->idev->absbit))
>  				continue;
> +			if (input_is_mt_value(abs))
> +				is_mt = true;
>  			virtinput_cfg_abs(vi, abs);
>  		}
>  	}
> +	if (is_mt)
> +		input_mt_init_slots(vi->idev,
> +				    CONFIG_VIRTIO_INPUT_MULTITOUCH_SLOTS,
> +				    INPUT_MT_DIRECT);


Do we need the number in config space maybe? And maybe with a feature
bit so host can find out whether guest supports MT?

>  
>  	virtio_device_ready(vdev);
>  	vi->ready = true;
> -- 
> 2.23.0

Re: [PATCH RESEND v2] virtio-input: add multi-touch support

[Vasyl Vavrychuk]

Hi, Dmitry,

Thanks for you suggestion. I have sent v3 version of the patch where I 
have applied it.

Kind regards,
Vasyl

On 09.12.20 00:05, Dmitry Torokhov wrote:
> CAUTION: This email originated from outside of the organization.
> Do not click links or open attachments unless you recognize the sender and know the content is safe.
> 
> 
> Hi Vasyl,
> 
> On Tue, Dec 08, 2020 at 11:01:50PM +0200, Vasyl Vavrychuk wrote:
>> From: Mathias Crombez <mathias.crombez@faurecia.com>
>>
>> Without multi-touch slots allocated, ABS_MT_SLOT events will be lost by
>> input_handle_abs_event.
>>
>> Signed-off-by: Mathias Crombez <mathias.crombez@faurecia.com>
>> Signed-off-by: Vasyl Vavrychuk <vasyl.vavrychuk@opensynergy.com>
>> Tested-by: Vasyl Vavrychuk <vasyl.vavrychuk@opensynergy.com>
>> ---
>> v2: fix patch corrupted by corporate email server
>>
>>   drivers/virtio/Kconfig        | 11 +++++++++++
>>   drivers/virtio/virtio_input.c |  8 ++++++++
>>   2 files changed, 19 insertions(+)
>>
>> diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig
>> index 7b41130d3f35..2cfd5b01d96d 100644
>> --- a/drivers/virtio/Kconfig
>> +++ b/drivers/virtio/Kconfig
>> @@ -111,6 +111,17 @@ config VIRTIO_INPUT
>>
>>         If unsure, say M.
>>
>> +config VIRTIO_INPUT_MULTITOUCH_SLOTS
>> +     depends on VIRTIO_INPUT
>> +     int "Number of multitouch slots"
>> +     range 0 64
>> +     default 10
>> +     help
>> +      Define the number of multitouch slots used. Default to 10.
>> +      This parameter is unused if there is no multitouch capability.
> 
> I believe the number of slots should be communicated to the guest by
> the host, similarly to how the rest of input device capabilities is
> transferred, instead of having static compile-time option.
> 
>> +
>> +      0 will disable the feature.
>> +
>>   config VIRTIO_MMIO
>>        tristate "Platform bus driver for memory mapped virtio devices"
>>        depends on HAS_IOMEM && HAS_DMA
>> diff --git a/drivers/virtio/virtio_input.c b/drivers/virtio/virtio_input.c
>> index f1f6208edcf5..13f3d90e6c30 100644
>> --- a/drivers/virtio/virtio_input.c
>> +++ b/drivers/virtio/virtio_input.c
>> @@ -7,6 +7,7 @@
>>
>>   #include <uapi/linux/virtio_ids.h>
>>   #include <uapi/linux/virtio_input.h>
>> +#include <linux/input/mt.h>
>>
>>   struct virtio_input {
>>        struct virtio_device       *vdev;
>> @@ -205,6 +206,7 @@ static int virtinput_probe(struct virtio_device *vdev)
>>        unsigned long flags;
>>        size_t size;
>>        int abs, err;
>> +     bool is_mt = false;
>>
>>        if (!virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
>>                return -ENODEV;
>> @@ -287,9 +289,15 @@ static int virtinput_probe(struct virtio_device *vdev)
>>                for (abs = 0; abs < ABS_CNT; abs++) {
>>                        if (!test_bit(abs, vi->idev->absbit))
>>                                continue;
>> +                     if (input_is_mt_value(abs))
>> +                             is_mt = true;
>>                        virtinput_cfg_abs(vi, abs);
>>                }
>>        }
>> +     if (is_mt)
>> +             input_mt_init_slots(vi->idev,
>> +                                 CONFIG_VIRTIO_INPUT_MULTITOUCH_SLOTS,
>> +                                 INPUT_MT_DIRECT);
> 
> Here errors need to be handled.
> 
>>
>>        virtio_device_ready(vdev);
>>        vi->ready = true;
>> --
>> 2.23.0
>>
> 
> Thanks.
> 
> --
> Dmitry
> 

Re: [PATCH RESEND v2] virtio-input: add multi-touch support

[Vasyl Vavrychuk]

On 09.12.20 10:28, Michael S. Tsirkin wrote:
> On Tue, Dec 08, 2020 at 11:01:50PM +0200, Vasyl Vavrychuk wrote:
>> From: Mathias Crombez <mathias.crombez@faurecia.com>
>> Cc: stable@vger.kernel.org
> 
> I don't believe this is appropriate for stable, looks like
> a new feature to me.

Agree, removed.

>>
>> +config VIRTIO_INPUT_MULTITOUCH_SLOTS
>> +     depends on VIRTIO_INPUT
>> +     int "Number of multitouch slots"
>> +     range 0 64
>> +     default 10
>> +     help
>> +      Define the number of multitouch slots used. Default to 10.
>> +      This parameter is unused if there is no multitouch capability.
>> +
>> +      0 will disable the feature.
>> +
> 
> Most people won't be using this config so the defaults matter. So why 10? 10 fingers?
> 
> And where does 64 come from?

I have sent v3 version where number of slots it obtained from the host.

>> +     if (is_mt)
>> +             input_mt_init_slots(vi->idev,
>> +                                 CONFIG_VIRTIO_INPUT_MULTITOUCH_SLOTS,
>> +                                 INPUT_MT_DIRECT);
> 
> 
> Do we need the number in config space maybe? And maybe with a feature
> bit so host can find out whether guest supports MT?

I think it is not applicable in v3 which I sent, because number of slots 
is commit from the host. So, now host controls whether guest support MT.