Re: [PATCH RFC 1/2] brcmfmac: remove interface before notifying listener
From: Arend van Spriel <arend.vanspriel@broadcom.com>
Date: 2016-06-18 19:26:44
Also in:
linux-wireless, lkml
On 18-06-16 20:18, Rafał Miłecki wrote:
So far when receiving event about in-firmware-interface removal we were notifying our listener and afterwards we were removing Linux interface.
[snip]
quoted hunk ↗ jump to hunk
diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fweh.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fweh.c index 9da7a4c..5fd1886 100644 --- 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"@@ -180,10 +181,16 @@ static void brcmf_fweh_handle_if_event(struct brcmf_pub *drvr, if (ifp && ifevent->action == BRCMF_E_IF_CHANGE) brcmf_fws_reset_interface(ifp); - err = brcmf_fweh_call_event_handler(ifp, emsg->event_code, emsg, data);
The reason for doing this first is because we are passing the ifp, which is netdev_priv(ifp->ndev). In brcmf_remove_interface() we only unregister the netdev, which will end up (after scheduling) in brcmf_free_netdev() thus freeing the ifp. By moving the event handler function ifp may be stale already.
+ if (ifp && ifevent->action == BRCMF_E_IF_DEL) {
+ bool rtnl_locked = brcmf_cfg80211_vif_event_armed(drvr->config);
+
+ brcmf_remove_interface(ifp, rtnl_locked);I guess rtnl_locked here means "rtnl_is_locked() by brcmfmac". It actually does not matter who is holding the rtnl_lock. At least when it is brcmfmac it is still a different task, ie. hostapd, iw, etc. Also when brcmf_cfg80211_vif_event_armed() return false there may still be some task holding the rtnl_lock. Regards, Arend