Re: request_firmware() backport to 2.4 kernels

[Marcel Holtmann <marcel@holtmann.org>]

Hi Manuel,

>  A while back request_firmware() was added to the 2.5 kernel series to
>  support firmware needing drivers keeping the firmware images in
>  userspace. And I also backported it to the 2.4 kernel series on top of
>  procfs, but Marcelo didn't answer emails relating to it (there where
>  probably other more important matters back then).
>  
>  Since then, the 2.4 backport has been deployed and tested with
>  orinoco_usb driver variant (http://orinoco-usb.alioth.debian.org/),
>  as you can see in the download statistics in alioth, there has been
>  more than 400 downloads of the request_firmware enabled version
>  (0.2.1). And drivers on the 2.5/2.6 series are being ported to use
>  request_firmware() interface.

I've tested your patch with 2.4.22-pre8 and a modified version of my
bfusb driver. It is working fine, but I get these log entries:

	hub.c: new USB device 02:0c.0-2, assigned address 2
	firmware_class.c:call_helper: firmware: /sbin/hotplug firmware add
	remove_proc_entry: bfusb003002/loading busy, count=1
	remove_proc_entry: firmware/bfusb003002 busy, count=1
	BlueFRITZ! USB loading firmware
	de_put: deferred delete of loading
	de_put: deferred delete of bfusb003002
	BlueFRITZ! USB device ready

Is this a problem of your patch or is it a general /proc problem?

>  Would it be possible to include it in the -aa kernel tree? That would
>  make it accessible to a wider audience for testing, and make it easier
>  for developers to backport their drivers to the 2.4
>  series.

The patch don't touches any other part of the Linux kernel, so I think
it is a nice and clean extension.

 Documentation/Configure.help                          |    6 
 Documentation/firmware_class/README                   |   58 +
 Documentation/firmware_class/firmware_sample_driver.c |  121 +++
 Documentation/firmware_class/hotplug-script           |   16 
 include/linux/firmware.h                              |   20 
 lib/Config.in                                         |    4 
 lib/Makefile                                          |    3 
 lib/firmware_class.c                                  |  557 ++++++++++++++++++
 8 files changed, 784 insertions(+), 1 deletion(-)

I already ported drivers/bluetooth/bfusb.c to use the request_firmware()
interface and I will port drivers/bluetooth/bt3c_cs.c after this patch
gets merged.

Regards

Marcel