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:
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>
> Hi Vasyl,
>
> On Tue, Dec 08, 2020 at 11:01:50PM +0200, Vasyl Vavrychuk wrote:
> > From: Mathias Crombez <mathias.crombez@xxxxxxxxxxxx>
> >
> > Without multi-touch slots allocated, ABS_MT_SLOT events will be lost by
> > input_handle_abs_event.
> >
> > Signed-off-by: Mathias Crombez <mathias.crombez@xxxxxxxxxxxx>
> > Signed-off-by: Vasyl Vavrychuk <vasyl.vavrychuk@xxxxxxxxxxxxxxx>
> > Tested-by: Vasyl Vavrychuk <vasyl.vavrychuk@xxxxxxxxxxxxxxx>
> > ---
> > 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