Re: loading firmware while usermodehelper disabled.

On 02/01/12 21:23, Linus Torvalds wrote:

On Mon, Jan 2, 2012 at 1:09 PM, Jack Stone [off-list ref] wrote:

quoted

What about USB "class" drivers e.g. usb-storage. They handle any device
that reports itself as a usb mass storage device. There could be a
device that needs to be bootstrapped before it becomes a generic usb
mass storage device. Do we really want to have to write a new driver
that is almost identical to the generic driver but handles the USB
firmware correctly.

I'd hope that the generic driver just expose enough interfaces that
you could basically do a "firmware-load" driver that just loads the
firmware and then attaches the device to the generic driver.

Sounds workable.

To make the firmware caching easier I would propose one extra function
in addition to the aforemensioned get_firmware / put_firmware - a
find_firmware function to search the cache and return the appropriate
firmware blob. It should only be called if the caller already has a
refcount to the firmware, it's only use is to save every driver saving a
pointer to the firmware.

If noone beats me to it I will try and put together an RFC for a new
version.

Thanks,

Jack