On Thu, 17 May 2007, Chris Frey wrote:
> Hi,
>
> Below is a patch with the following changes to the berry_charge.c module:
>
> 1) kzalloc() is called, but memory is never freed
>
> Is this a memory leak? I'm not sure, but the buffer is only
> a dummy buffer to hold return data that is never used,
> so I suspect a stack variable will suffice.
Are you aware that stack-based DMA buffers don't work on all systems?
> @@ -105,6 +128,28 @@
> /* turn the power on */
> magic_charge(udev);
>
> + /* change modes if device is a Pearl */
> + if (udev->descriptor.idProduct == PEARL)
> + magic_pearl(udev);
> +
> + /* set configuration and reset to activate change */
> + dbg(&udev->dev, "Calling set_configuration\n");
> + retval = usb_driver_set_configuration(udev, 1);
> + if (retval) {
> + dev_err(&udev->dev, "Set Configuration failed :%d.\n", retval);
> + return retval;
> + }
Apparently you don't understand how usb_driver_set_configuration()
works. It doesn't set the configuration immediately; in fact the
Set-Config doesn't happen until after your driver returns.
Note that if the config you are changing to is the same as the current
config then there's no need to use usb_driver_set_configuration(). You
can call usb_reset_configuration() instead -- it sends a Set-Config
request for the current configuration number.
Furthermore, if the device has changed its set of available
configurations then at some point you _must_ call usb_reset_device().
Otherwise the kernel will be unaware of the new configs.
> + /* reset is required by the Pearl */
> + retval = usb_reset_configuration(udev);
> + if (retval) {
> + dev_err(&udev->dev, "Configuration reset failed: %d.\n",
> retval);
> + return retval;
> + }
usb_reset_configuration() doesn't do a device reset; it does a
Set-Config. Is that what you want? Or do you want to call
usb_reset_device()?
Alan Stern
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