[Spice-devel] [PATCH v7 04/14] GUdevClient: Do not process USB hotplug events while redirection is in progress

[Jonathon Jongsma]

Previously acked

Acked-by: Jonathon Jongsma <jjongsma at redhat.com>


On Tue, 2016-03-08 at 16:05 +0200, Dmitry Fleytman wrote:
> From: Kirill Moizik <kmoizik at redhat.com>
> 
> USB redirection flow on Windows includes a number of reset requests issued
> to the port that hosts the device deing redirected.
> 
> Each port reset emulates device removal and reinsertion and produces
> corresponding hotplug events and a number of device list updates on
> different levels of USB stack and USB redirection engine.
> 
> As a result, queriyng USB device list performed by spice-gtk's hotplug
> event handler may return inconsistent results if performed in parallel
> to redirection flow.
> 
> This patch suppresses handling of USB hotplug events during redirection
> and injects a simulated hotplug event after redirection completion
> in order to properly process real device list changes in case they
> happened during the redirection flow.
> 
> Signed-off-by: Kirill Moizik <kmoizik at redhat.com>
> Signed-off-by: Dmitry Fleytman <dfleytma at redhat.com>
> ---
>  src/win-usb-dev.c | 19 +++++++++++++++++++
>  1 file changed, 19 insertions(+)
> 
> diff --git a/src/win-usb-dev.c b/src/win-usb-dev.c
> index 0e86d39..1cf9f21 100644
> --- a/src/win-usb-dev.c
> +++ b/src/win-usb-dev.c
> @@ -293,6 +293,8 @@ static void g_udev_client_get_property(GObject    
>  *gobject,
>      }
>  }
>  
> +static void handle_dev_change(GUdevClient *self);
> +
>  static void g_udev_client_set_property(GObject       *gobject,
>                                         guint          prop_id,
>                                         const GValue  *value,
> @@ -300,10 +302,18 @@ static void g_udev_client_set_property(GObject      
>  *gobject,
>  {
>      GUdevClient *self = G_UDEV_CLIENT(gobject);
>      GUdevClientPrivate *priv = self->priv;
> +    gboolean old_val;
>  
>      switch (prop_id) {
>      case PROP_REDIRECTING:
> +        old_val = priv->redirecting;
>          priv->redirecting = g_value_get_boolean(value);
> +        if (old_val && !priv->redirecting) {
> +            /* This is a redirection completion case.
> +               Inject hotplug event in case we missed device changes
> +               during redirection processing. */
> +            handle_dev_change(self);
> +        }
>          break;
>      default:
>          G_OBJECT_WARN_INVALID_PROPERTY_ID(gobject, prop_id, pspec);
> @@ -412,6 +422,15 @@ static void handle_dev_change(GUdevClient *self)
>      GError *err = NULL;
>      GList *now_devs = NULL;
>  
> +    if (priv->redirecting == TRUE) {
> +        /* On Windows, querying USB device list may return inconsistent
> results
> +           if performed in parallel to redirection flow.
> +           A simulated hotplug event will be injected after redirection
> +           completion in order to process real device list changes that may
> +           had taken place during redirection process. */
> +        return;
> +    }
> +
>      if(g_udev_client_list_devices(self, &now_devs, &err, __FUNCTION__) < 0) {
>          g_warning("could not retrieve device list");
>          return;