[Qemu-devel] Re: [PATCHv3 10/14] Add get_dev_path callback for usb bus.

[Blue Swirl <blauwirbel@gmail.com>]

On Wed, Nov 10, 2010 at 5:14 PM, Gleb Natapov <gleb@redhat.com> wrote:
>
> Signed-off-by: Gleb Natapov <gleb@redhat.com>
> ---
>  hw/usb-bus.c |   35 +++++++++++++++++++++++++++++++++++
>  1 files changed, 35 insertions(+), 0 deletions(-)
>
> diff --git a/hw/usb-bus.c b/hw/usb-bus.c
> index 256b881..6292282 100644
> --- a/hw/usb-bus.c
> +++ b/hw/usb-bus.c
> @@ -5,11 +5,13 @@
>  #include "monitor.h"
>
>  static void usb_bus_dev_print(Monitor *mon, DeviceState *qdev, int indent);
> +static char *usbbus_get_fw_dev_path(DeviceState *dev);
>
>  static struct BusInfo usb_bus_info = {
>     .name      = "USB",
>     .size      = sizeof(USBBus),
>     .print_dev = usb_bus_dev_print,
> +    .get_fw_dev_path = usbbus_get_fw_dev_path,
>  };
>  static int next_usb_bus = 0;
>  static QTAILQ_HEAD(, USBBus) busses = QTAILQ_HEAD_INITIALIZER(busses);
> @@ -307,3 +309,36 @@ USBDevice *usbdevice_create(const char *cmdline)
>     }
>     return usb->usbdevice_init(params);
>  }
> +
> +static int usbbus_get_fw_dev_path_helper(USBDevice *d, USBBus *bus, char *p,
> +                                         int len)
> +{
> +    int l = 0;
> +    USBPort *port;
> +
> +    QTAILQ_FOREACH(port, &bus->used, next) {
> +        if (port->dev != d)

Braces.

> +            continue;
> +
> +        if (port->pdev) {
> +            l = usbbus_get_fw_dev_path_helper(port->pdev, bus, p, len);
> +        }
> +        l += snprintf(p + l, len - l, "%s@%x/", qdev_fw_name(&d->qdev),
> +                      port->index);
> +        return l;
> +    }
> +    return 0;

With this return value...

> +}
> +
> +static char *usbbus_get_fw_dev_path(DeviceState *dev)
> +{
> +    USBDevice *d = (USBDevice*)dev;
> +    USBBus *bus = usb_bus_from_device(d);
> +    char path[100];
> +    int l;
> +
> +    l = usbbus_get_fw_dev_path_helper(d, bus, path, sizeof(path));
> +    path[l-1] = '\0';

...this statement will have undesirable effects...

> +
> +    return strdup(path);

...like this.