[Spice-devel] [spice-gtk PATCH v3] Avoid compression of isochronous devices

[Marc-André Lureau]

Hi

----- Original Message -----
> Device is considered isochronous if one of its endpoints is
> defined as isochronous transfer, in that case data transfer
> over the usbredir channel will not be compressed
> (it is assumed that there is a strong correlation between
> isochronous devices and devices which their data is usually
> compressed)
> 
> E.g.
> Camera/mic device will usually be recognised as isochronous
> while storage devices won't
> ---
>  src/channel-usbredir.c        |  9 +++++++++
>  src/usb-device-manager-priv.h |  1 +
>  src/usb-device-manager.c      | 34 ++++++++++++++++++++++++++++++++++
>  3 files changed, 44 insertions(+)
> 
> diff --git a/src/channel-usbredir.c b/src/channel-usbredir.c
> index dd17e6c..2d025f5 100644
> --- a/src/channel-usbredir.c
> +++ b/src/channel-usbredir.c
> @@ -544,6 +544,11 @@ void
> spice_usbredir_channel_disconnect_device_async(SpiceUsbredirChannel *channe
>      g_object_unref(task);
>  }
>  
> +static SpiceUsbDevice
> *spice_usbredir_channel_get_spice_usb_device(SpiceUsbredirChannel *channel)
> +{
> +    return channel->priv->spice_device;
> +}
> +
>  G_GNUC_INTERNAL
>  libusb_device *spice_usbredir_channel_get_device(SpiceUsbredirChannel
>  *channel)
>  {
> @@ -673,6 +678,10 @@ static int try_write_compress_LZ4(SpiceUsbredirChannel
> *channel, uint8_t *data,
>          /* No server compression capability - data will not be compressed */
>          return FALSE;
>      }
> +
> if(spice_usb_device_is_isochronous(spice_usbredir_channel_get_spice_usb_device(channel)))
> {
> +        /* Don't compress - one of the device endpoints is isochronous */
> +        return FALSE;
> +    }
>      bound = LZ4_compressBound(count);
>      if (bound == 0) {
>          /* Invalid bound - data will not be compressed */
> diff --git a/src/usb-device-manager-priv.h b/src/usb-device-manager-priv.h
> index b6fa9c9..83884d7 100644
> --- a/src/usb-device-manager-priv.h
> +++ b/src/usb-device-manager-priv.h
> @@ -40,6 +40,7 @@ guint8 spice_usb_device_get_busnum(const SpiceUsbDevice
> *device);
>  guint8 spice_usb_device_get_devaddr(const SpiceUsbDevice *device);
>  guint16 spice_usb_device_get_vid(const SpiceUsbDevice *device);
>  guint16 spice_usb_device_get_pid(const SpiceUsbDevice *device);
> +gboolean spice_usb_device_is_isochronous(const SpiceUsbDevice *device);
>  
>  #endif
>  
> diff --git a/src/usb-device-manager.c b/src/usb-device-manager.c
> index f076967..f117683 100644
> --- a/src/usb-device-manager.c
> +++ b/src/usb-device-manager.c
> @@ -153,6 +153,7 @@ typedef struct _SpiceUsbDeviceInfo {
>      guint8  devaddr;
>      guint16 vid;
>      guint16 pid;
> +    gboolean isochronous;
>  #ifdef G_OS_WIN32
>      guint8  state;
>  #else
> @@ -2017,6 +2018,29 @@ gchar *spice_usb_device_get_description(SpiceUsbDevice
> *device, const gchar *for
>  
>  
>  #ifdef USE_USBREDIR
> +static gboolean probe_isochronous_endpoint(libusb_device *libdev) {
> +    struct libusb_config_descriptor * conf_desc;
> +    gboolean isoc_found = FALSE;
> +    gint i,j,k;
> +
> +    g_return_val_if_fail(libdev != NULL, FALSE);
> +    g_return_val_if_fail(!libusb_get_active_config_descriptor(libdev,
> &conf_desc), FALSE);
> +

It's not a good idea to put code with side-effect in g_return, as it could be removed with  G_DISABLE_CHECKS (unlikely)

I'll touch it on commit.

thanks


> +    for(i = 0; !isoc_found && i < conf_desc->bNumInterfaces; i++) {
> +        for(j = 0; !isoc_found && j <
> conf_desc->interface[i].num_altsetting; j++) {
> +            for(k = 0; !isoc_found && k <
> conf_desc->interface[i].altsetting[j].bNumEndpoints;k++) {
> +                gint attributes =
> conf_desc->interface[i].altsetting[j].endpoint[k].bmAttributes;
> +                gint type = attributes & LIBUSB_TRANSFER_TYPE_MASK;
> +                if (type == LIBUSB_TRANSFER_TYPE_ISOCHRONOUS)
> +                    isoc_found = TRUE;
> +            }
> +        }
> +    }
> +
> +    libusb_free_config_descriptor(conf_desc);
> +    return isoc_found;
> +}
> +
>  /*
>   * SpiceUsbDeviceInfo
>   */
> @@ -2042,6 +2066,7 @@ static SpiceUsbDeviceInfo
> *spice_usb_device_new(libusb_device *libdev)
>      info->vid = vid;
>      info->pid = pid;
>      info->ref = 1;
> +    info->isochronous = probe_isochronous_endpoint(libdev);
>  #ifndef G_OS_WIN32
>      info->libdev = libusb_ref_device(libdev);
>  #endif
> @@ -2085,6 +2110,15 @@ guint16 spice_usb_device_get_pid(const SpiceUsbDevice
> *device)
>      return info->pid;
>  }
>  
> +gboolean spice_usb_device_is_isochronous(const SpiceUsbDevice *device)
> +{
> +    const SpiceUsbDeviceInfo *info = (const SpiceUsbDeviceInfo *)device;
> +
> +    g_return_val_if_fail(info != NULL, 0);
> +
> +    return info->isochronous;
> +}
> +
>  #ifdef G_OS_WIN32
>  void spice_usb_device_set_state(SpiceUsbDevice *device, guint8 state)
>  {
> --
> 2.5.5
> 
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