[LEDE-DEV] [PATCH v1 1/2] base-files, mac80211, broadcom-wl: plug-and-play wifi detection

[Matthias Schiffer]

On 10/07/2016 08:10 PM, Christian Lamparter wrote:
> Currently, the wifi detection script is executed as part of
> the (early) boot process. Pluggable wifi USB devices, which
> are inserted at a later time are not automatically
> detected and therefore they don't show up in LuCI.
> 
> A user has to deal with wifi detection manually, or restart
> the router.
> 
> However, the current "sleep 1" window - which the boot
> process waits for wifi devices to "settle down" - is too
> short to detect wifi devices for some routers.
> 
> For example, this can happen with USB WLAN devices on the
> WNDR4700. This is because the usb controller needs to load
> its firmware from UBI and initialize, before it can operate.
> 
> The issue can be seen on a BT HomeHub 5A as well as soon as
> the caldata are on an ubi volume. This is because the ath9k
> card has to be initialized by owl-loader first. Which has to
> wait for the firmware extraction script to retrieve the pci
> initialization values inside the caldata.
> 
> This patch moves the wifi detection to hotplug scripts.
> For mac80211, the wifi detection will now automatically
> run any time a "ieee80211" device is added. Likewise
> broadcom-wl's script checks for new "net" devices.
> 
> As for potential problems:
> - For devices with more than one wifi device, these scripts
>   will run multiple times during boot (concurrently).
>   For this reason, the script uses file locking to prevent
>   races during discovery. (i.e duplicated radio instances).
> 
> - The broadcom-wl hotplug script is suboptimal.
>   As it will run for any net devices (ethernet).
> 
> (- There might be non-wifi drivers that needed this delay)
> 
> All changes to base-files, mac80211 and broadcom-wl packages
> have been integrated into a single patch to play nice with
> git bisect.
> 
> Thanks to Martin Blumenstingl for helping with the implementation
> and testing of the patch.
> 
> Signed-off-by: Mathias Kresin <dev at kresin.me>
> Signed-off-by: Christian Lamparter <chunkeey at gmail.com>
> ---
> We would like to hear, if these changes work with broadcom-wl.
> (Felix removed the hostap, so this isn't included anymore).
> 
> trap and lock are part of the default busybox setup.

Hi,
it would be great to remove the direct write of /etc/config/wireless
completely, as it won't lock against other users of UCI that modify the
wireless config. IMO, it should just use UCI to modify the configuration as
everything else does.

Regards,
Matthias


> ---
>  package/base-files/files/etc/init.d/boot                 |  9 ---------
>  .../files/etc/hotplug.d/net/00-broadcom-wifi-detect      | 16 ++++++++++++++++
>  package/kernel/mac80211/Makefile                         |  2 ++
>  package/kernel/mac80211/files/mac80211.hotplug           | 16 ++++++++++++++++
>  4 files changed, 34 insertions(+), 9 deletions(-)
>  create mode 100644 package/kernel/broadcom-wl/files/etc/hotplug.d/net/00-broadcom-wifi-detect
>  create mode 100644 package/kernel/mac80211/files/mac80211.hotplug
> 
> diff --git a/package/base-files/files/etc/init.d/boot b/package/base-files/files/etc/init.d/boot
> index 904f7db..1d61f2f 100755
> --- a/package/base-files/files/etc/init.d/boot
> +++ b/package/base-files/files/etc/init.d/boot
> @@ -38,15 +38,6 @@ boot() {
>  
>  	/sbin/kmodloader
>  
> -	# allow wifi modules time to settle
> -	sleep 1
> -
> -	/sbin/wifi detect > /tmp/wireless.tmp
> -	[ -s /tmp/wireless.tmp ] && {
> -		cat /tmp/wireless.tmp >> /etc/config/wireless
> -	}
> -	rm -f /tmp/wireless.tmp
> -
>  	/bin/config_generate
>  	uci_apply_defaults
>  	
> diff --git a/package/kernel/broadcom-wl/files/etc/hotplug.d/net/00-broadcom-wifi-detect b/package/kernel/broadcom-wl/files/etc/hotplug.d/net/00-broadcom-wifi-detect
> new file mode 100644
> index 0000000..cd7af8b
> --- /dev/null
> +++ b/package/kernel/broadcom-wl/files/etc/hotplug.d/net/00-broadcom-wifi-detect
> @@ -0,0 +1,16 @@
> +#!/bin/sh
> +
> +unlock() {
> +	lock -u /tmp/wireless.lock
> +}
> +
> +[ "${ACTION}" = "add" ] && {
> +	trap unlock EXIT
> +	lock /tmp/wireless.lock
> +
> +	/sbin/wifi detect > /tmp/wireless.tmp
> +
> +	[ -s /tmp/wireless.tmp ] && cat /tmp/wireless.tmp >> /etc/config/wireless
> +
> +	rm -f /tmp/wireless.tmp
> +}
> diff --git a/package/kernel/mac80211/Makefile b/package/kernel/mac80211/Makefile
> index 91c9362..f320326 100644
> --- a/package/kernel/mac80211/Makefile
> +++ b/package/kernel/mac80211/Makefile
> @@ -1732,6 +1732,8 @@ define KernelPackage/cfg80211/install
>  	$(INSTALL_DIR) $(1)/lib/wifi $(1)/lib/netifd/wireless
>  	$(INSTALL_DATA) ./files/lib/wifi/mac80211.sh $(1)/lib/wifi
>  	$(INSTALL_BIN) ./files/lib/netifd/wireless/mac80211.sh $(1)/lib/netifd/wireless
> +	$(INSTALL_DIR) $(1)/etc/hotplug.d/ieee80211
> +	$(INSTALL_DATA) ./files/mac80211.hotplug $(1)/etc/hotplug.d/ieee80211/00-wifi-detect
>  endef
>  
>  define KernelPackage/ipw2100/install
> diff --git a/package/kernel/mac80211/files/mac80211.hotplug b/package/kernel/mac80211/files/mac80211.hotplug
> new file mode 100644
> index 0000000..cd7af8b
> --- /dev/null
> +++ b/package/kernel/mac80211/files/mac80211.hotplug
> @@ -0,0 +1,16 @@
> +#!/bin/sh
> +
> +unlock() {
> +	lock -u /tmp/wireless.lock
> +}
> +
> +[ "${ACTION}" = "add" ] && {
> +	trap unlock EXIT
> +	lock /tmp/wireless.lock
> +
> +	/sbin/wifi detect > /tmp/wireless.tmp
> +
> +	[ -s /tmp/wireless.tmp ] && cat /tmp/wireless.tmp >> /etc/config/wireless
> +
> +	rm -f /tmp/wireless.tmp
> +}
> 


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