mac80211: backport brcmfmac changes from 2016-07-08

To work correctly hostapd requires wireless driver to allow interfaces
removal. It was working with brcmfmac only partially. Firmware for
BCM43602 got some special hack (feature?) that allowed removing all
interfaces by disabling mbss mode. It wasn't working with BCM4366
firmware and remaining interfaces were preventing hostapd from starting
again.

Those patches add support for "interface_remove" firmware method which
works with BCM4366 firmware and they make it finally possible to use
BCM4366 & brcmfmac & multiple interfaces.

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>

1 files changed, 75 insertions, 0 deletions

diff --git a/package/kernel/mac80211/patches/319-0005-brcmfmac-delete-interface-directly-in-code-that-sent.patch b/package/kernel/mac80211/patches/319-0005-brcmfmac-delete-interface-directly-in-code-that-sent.patch
new file mode 100644
index 0000000..12d7eb4
--- /dev/null
+++ b/package/kernel/mac80211/patches/319-0005-brcmfmac-delete-interface-directly-in-code-that-sent.patch
@@ -0,0 +1,75 @@
+From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <zajec5@gmail.com>
+Date: Wed, 29 Jun 2016 21:54:26 +0200
+Subject: [PATCH] brcmfmac: delete interface directly in code that sent fw
+ request
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+So far when receiving event about in-firmware-interface removal our
+event worker was notifying listener and afterwards it was removing Linux
+interface.
+
+First of all it was resulting in slightly unexpected order. The listener
+(del_virtual_intf callback) was (usually) returning with success before
+we even called unregister_netdev(ice).
+
+Please note this couldn't be simply fixed by changing order of calls in
+brcmf_fweh_handle_if_event as unregistering interface earlier could free
+struct brcmf_if.
+
+Another problem of current implementation are possible lockups. Focus on
+the time slot between calling event handler and removing Linux
+interface. During that time original caller may leave (unlocking rtnl
+semaphore) *and* another call to the same code may be done (locking it
+again). If that happens our event handler will stuck at removing Linux
+interface, it won't handle another event and will block process holding
+rtnl lock.
+
+This can be simply solved by unregistering interface in a proper
+callback, right after receiving confirmation event from firmware. This
+only required modifying worker to don't unregister on its own if there
+is someone waiting for the event.
+
+Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
+Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
+---
+
+--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fweh.c
++++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fweh.c
+@@ -18,6 +18,7 @@
+ #include "brcmu_wifi.h"
+ #include "brcmu_utils.h"
+ 
++#include "cfg80211.h"
+ #include "core.h"
+ #include "debug.h"
+ #include "tracepoint.h"
+@@ -182,8 +183,13 @@ static void brcmf_fweh_handle_if_event(s
+ 
+ 	err = brcmf_fweh_call_event_handler(ifp, emsg->event_code, emsg, data);
+ 
+-	if (ifp && ifevent->action == BRCMF_E_IF_DEL)
+-		brcmf_remove_interface(ifp, false);
++	if (ifp && ifevent->action == BRCMF_E_IF_DEL) {
++		bool armed = brcmf_cfg80211_vif_event_armed(drvr->config);
++
++		/* Default handling in case no-one waits for this event */
++		if (!armed)
++			brcmf_remove_interface(ifp, false);
++	}
+ }
+ 
+ /**
+--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c
++++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c
+@@ -2290,8 +2290,7 @@ int brcmf_p2p_del_vif(struct wiphy *wiph
+ 		else
+ 			err = 0;
+ 	}
+-	if (err)
+-		brcmf_remove_interface(vif->ifp, true);
++	brcmf_remove_interface(vif->ifp, true);
+ 
+ 	brcmf_cfg80211_arm_vif_event(cfg, NULL);
+ 	if (vif->wdev.iftype != NL80211_IFTYPE_P2P_DEVICE)