Re: [PATCH] [RFC] usb: gadget: composite: Allow idVendor and other module_params to be writable

[Michal Nazarewicz <mina86@mina86.com>]

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On Thu, Feb 21 2013, John Stultz wrote:
> In many cases, documentation around composite drivers suggest
> setting the idVendor and other module params as follows:
>
> $ insmod g_ffs.ko idVendor=<ID> iSerialNumber=<string>
>
> However, this won't work if the driver is not compiled in as a
> module, as the module_param permissions are S_IRUGO.
>
> Thus this patch changes the composite module_param permissions
> to S_IRUGO|S_IWUSR to allow the module_params to be set at
> runtime via /sys/modules/<driver>/parameters/

If the driver is not compiled as a module, setting those variables won't
work anyway.  Or am I missing something?

You can, however, pass them on Linux command line (with some prefix
which I can never remember).

If you want to configure things at run-time without having to compile
stuff as modules, you need to wait for the configfs based gadgets.

> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
> Cc: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
> Cc: Michal Nazarewicz <mina86@mina86.com>
> Cc: Felipe Balbi <balbi@ti.com>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: linux-usb@vger.kernel.org
> Signed-off-by: John Stultz <john.stultz@linaro.org>
> ---
>  include/linux/usb/composite.h |   16 ++++++++++------
>  1 file changed, 10 insertions(+), 6 deletions(-)
>
> diff --git a/include/linux/usb/composite.h b/include/linux/usb/composite.h
> index b09c37e..22b1b02 100644
> --- a/include/linux/usb/composite.h
> +++ b/include/linux/usb/composite.h
> @@ -399,24 +399,28 @@ struct usb_composite_overwrite {
>  #define USB_GADGET_COMPOSITE_OPTIONS()					\
>  	static struct usb_composite_overwrite coverwrite;		\
>  									\
> -	module_param_named(idVendor, coverwrite.idVendor, ushort, S_IRUGO); \
> +	module_param_named(idVendor, coverwrite.idVendor, ushort,	\
> +			S_IRUGO|S_IWUSR);				\
>  	MODULE_PARM_DESC(idVendor, "USB Vendor ID");			\
>  									\
> -	module_param_named(idProduct, coverwrite.idProduct, ushort, S_IRUGO); \
> +	module_param_named(idProduct, coverwrite.idProduct, ushort,	\
> +			S_IRUGO|S_IWUSR);				\
>  	MODULE_PARM_DESC(idProduct, "USB Product ID");			\
>  									\
> -	module_param_named(bcdDevice, coverwrite.bcdDevice, ushort, S_IRUGO); \
> +	module_param_named(bcdDevice, coverwrite.bcdDevice, ushort,	\
> +			S_IRUGO|S_IWUSR);				\
>  	MODULE_PARM_DESC(bcdDevice, "USB Device version (BCD)");	\
>  									\
>  	module_param_named(iSerialNumber, coverwrite.serial_number, charp, \
> -			S_IRUGO); \
> +			S_IRUGO|S_IWUSR);				\
>  	MODULE_PARM_DESC(iSerialNumber, "SerialNumber string");		\
>  									\
>  	module_param_named(iManufacturer, coverwrite.manufacturer, charp, \
> -			S_IRUGO); \
> +			S_IRUGO|S_IWUSR);				\
>  	MODULE_PARM_DESC(iManufacturer, "USB Manufacturer string");	\
>  									\
> -	module_param_named(iProduct, coverwrite.product, charp, S_IRUGO); \
> +	module_param_named(iProduct, coverwrite.product, charp,		\
> +			S_IRUGO|S_IWUSR);				\
>  	MODULE_PARM_DESC(iProduct, "USB Product string")
>  
>  void usb_composite_overwrite_options(struct usb_composite_dev *cdev,
> -- 
> 1.7.10.4
>

-- 
Best regards,                                         _     _
.o. | Liege of Serenely Enlightened Majesty of      o' \,=./ `o
..o | Computer Science,  Michał “mina86” Nazarewicz    (o o)
ooo +----<email/xmpp: mpn@google.com>--------------ooO--(_)--Ooo--

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