[V2,next] brcmfmac: don't remove interface on link down firmware event

Commit Message

Rafał Miłecki May 30, 2016, 4:40 a.m. UTC

There are two firmware events we handle similarly in brcmfmac:
BRCMF_E_LINK and BRCMF_E_IF. The difference from firmware point of view
is that the first one means BSS remains present in the firmware. Trying
to (re)create it (e.g. when adding new virtual interface) will result in
an error.

Current code treats both events in a similar way. It removes Linux
interface for each of them. It works OK with e.g. BCM43602. Its firmware
generates both events for each interface. It means we get BRCMF_E_LINK
and remove interface. That is soon followed by BRCMF_E_IF which means
BSS was also removed in a firmware. The only downside of this is a
harmless error like:
[  208.643180] brcmfmac: brcmf_fweh_call_event_handler: no interface object

Unfortunately BCM4366 firmware doesn't automatically remove BSS and so
it doesn't generate BRCMF_E_IF. In such case we incorrectly remove Linux
interface on BRCMF_E_LINK as BSS is still present in the firmware. It
results in an error when trying to re-create virtual interface, e.g.:
> iw phy phy1 interface add wlan1-1 type __ap
[ 3602.929199] brcmfmac: brcmf_ap_add_vif: timeout occurred
command failed: I/O error (-5)

With this patch we don't remove Linux interface while firmware keeps
BSS. Thanks to this we keep a consistent states of host driver and
device firmware.

Further improvement should be to mark BSS as disabled and remove
interface on BRCMF_E_LINK. Then we should add support for reusing
BSS-es.

Signed-off-by: Rafał Miłecki <[e-mail]>
---
V2: Fix drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c:5431:19: warning: unused variable ‘ifp’ [-Wunused-variable]
---
 drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c | 3 ---
 1 file changed, 3 deletions(-)

Comments

Kalle Valo June 16, 2016, 3:12 p.m. UTC | #1

Rafał Miłecki wrote:
> There are two firmware events we handle similarly in brcmfmac:
> BRCMF_E_LINK and BRCMF_E_IF. The difference from firmware point of view
> is that the first one means BSS remains present in the firmware. Trying
> to (re)create it (e.g. when adding new virtual interface) will result in
> an error.
> 
> Current code treats both events in a similar way. It removes Linux
> interface for each of them. It works OK with e.g. BCM43602. Its firmware
> generates both events for each interface. It means we get BRCMF_E_LINK
> and remove interface. That is soon followed by BRCMF_E_IF which means
> BSS was also removed in a firmware. The only downside of this is a
> harmless error like:
> [  208.643180] brcmfmac: brcmf_fweh_call_event_handler: no interface object
> 
> Unfortunately BCM4366 firmware doesn't automatically remove BSS and so
> it doesn't generate BRCMF_E_IF. In such case we incorrectly remove Linux
> interface on BRCMF_E_LINK as BSS is still present in the firmware. It
> results in an error when trying to re-create virtual interface, e.g.:
> > iw phy phy1 interface add wlan1-1 type __ap
> [ 3602.929199] brcmfmac: brcmf_ap_add_vif: timeout occurred
> command failed: I/O error (-5)
> 
> With this patch we don't remove Linux interface while firmware keeps
> BSS. Thanks to this we keep a consistent states of host driver and
> device firmware.
> 
> Further improvement should be to mark BSS as disabled and remove
> interface on BRCMF_E_LINK. Then we should add support for reusing
> BSS-es.
> 
> Signed-off-by: Rafał Miłecki <[e-mail]>

Thanks, 1 patch applied to wireless-drivers-next.git:

fd3667a8d1cb brcmfmac: don't remove interface on link down firmware event

Patch

diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
index 38df1be..d23b95e 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
@@ -5428,7 +5428,6 @@  brcmf_notify_connect_status_ap(struct brcmf_cfg80211_info *cfg,
 			       struct net_device *ndev,
 			       const struct brcmf_event_msg *e, void *data)
 {
-	struct brcmf_if *ifp = netdev_priv(ndev);
 	static int generation;
 	u32 event = e->event_code;
 	u32 reason = e->reason;
@@ -5439,8 +5438,6 @@  brcmf_notify_connect_status_ap(struct brcmf_cfg80211_info *cfg,
 	    ndev != cfg_to_ndev(cfg)) {
 		brcmf_dbg(CONN, "AP mode link down\n");
 		complete(&cfg->vif_disabled);
-		if (ifp->vif->mbss)
-			brcmf_remove_interface(ifp);
 		return 0;
 	}