2016-07-13 13:20 GMT+02:00 Arend Van Spriel <arend.vanspr...@broadcom.com>:
> On 12-7-2016 12:23, Per Förlin wrote:
>> 2016-07-12 11:48 GMT+02:00 Arend Van Spriel <arend.vanspr...@broadcom.com>:
>>>
>>>
>>> On 12-7-2016 10:35, Per Förlin wrote:
>>>> 2016-07-06 11:53 GMT+02:00 Per Förlin <per.for...@gmail.com>:
>>>>> I have now verified this patch on backports 4.4.
>>>>>
>>>>> 2016-04-12 23:55 GMT+02:00 <per.for...@gmail.com>:
>>>>>> From: Per Forlin <per.for...@gmail.com>
>>>>>>
>>>>>> This patch resolves an issue where pend_8021x_cnt was not decreased
>>>>>> on txfinalize. This caused brcmf_netdev_wait_pend8021x to timeout
>>>>>> because the counter indicated pending packets.
>>>>>>
>>>>>> WARNING: at .../brcmfmac/core.c:1289 brcmf_netdev_wait_pend8021x
>>>>>> (warn_slowpath_common)
>>>>>> (warn_slowpath_null)
>>>>>> (brcmf_netdev_wait_pend8021x [brcmfmac])
>>>>>> (send_key_to_dongle [brcmfmac])
>>>>>> (brcmf_cfg80211_del_key [brcmfmac])
>>>>>> (nl80211_del_key [cfg80211])
>>>>>> (genl_rcv_msg)
>>>>>> (netlink_rcv_skb)
>>>>>> (genl_rcv)
>>>>>> (netlink_unicast)
>>>>>> (netlink_sendmsg)
>>>>>> (sock_sendmsg)
>>>>>> (___sys_sendmsg)
>>>>>> (__sys_sendmsg)
>>>>>> (SyS_sendmsg)
>>>>>>
>>>>>> The solution is to pull back the header offset in case
>>>>>> of an error in txdata(), which may happen in case of
>>>> Clarification:
>>>>
>>>> txdata=brcmf_proto_bcdc_txdata()
>>>> brcmf_proto_bcdc_txdata(): Calls brcmf_proto_bcdc_hdrpush()
>>>>
>>>> The header needs to be pulled back in case of error otherwise
>>>> the error handling and cleanup up will fail to decrease the counter
>>>> of pending packets.
>>>
>>> Yes, this part of the patch is clear to me.
>>>
>> Thanks, I wasn't sure.
>>
>>>>>> packet overload in brcmf_sdio_bus_txdata.
>>>>>>
>>>>>> Overloading an WLAN interface is not an unlikely scenario.
>>>
>>> So here is where things start to look suspicious and I have mentioned
>>> this before. My thought here was "How the hell can you end up with a
>>> 2048 packets on the sdio queue", which I mentioned to you before. There
>>> is a high watermark on the queue upon which we do a netif_stop_queue()
>>> so network layer does not keep pushing tx packets our way. Looking
>>> further into this I found that we introduced a bug with commit
>>> 9cd18359d31e ("brcmfmac: Make FWS queueing configurable.") so we ended
>>> up doing nothing except increasing as statistics debug counter :-(
>>>
>> Is there a fix available for the high watermark issue or is it
>> something you will look into?
>>
>> To produce a load on the wlan interface I run
>> iperf -c 239.255.1.3 -u -b 10m -f m -i 60 -t 3000
>> and this is enough in my case to fill up the 2048 queue.
>>
>>>>>> In case of packet overload the error print "out of bus->txq"
>>>>>> is very verbose. To reduce SPAM degrade it to a debug print.
>>>>>>
>>>>>> Signed-off-by: Per Forlin <per.for...@gmail.com>
>>>>>> ---
>>>>>> Change log:
>>>>>> v2 - Add variable to know whether the counter is increased or not
>>>>>> v3 - txfinalize should decrease the counter. Adjust skb header offset
>>>>>> v4 - Fix build error
>>>>>>
>>>>>> drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c | 4 ++++
>>>>>> drivers/net/wireless/broadcom/brcm80211/brcmfmac/fwsignal.c | 4 +++-
>>>>>> drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c | 2 +-
>>>>>> 3 files changed, 8 insertions(+), 2 deletions(-)
>>>>>>
>>>>>> diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c
>>>>>> b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c
>>>>>> index ed9998b..f342f7c 100644
>>>>>> --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c
>>>>>> +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c
>>>>>> @@ -541,6 +541,9 @@ void brcmf_txfinalize(struct brcmf_if *ifp, struct
>>>>>> sk_buff *txp, bool success)
>>>>>> struct ethhdr *eh;
>>>>>> u16 type;
>>>>>>
>>>>>> + if (!ifp)
>>>>>> + goto free;
>>>>>> +
>>>
>>> This may not be needed.
>>>
>> This is not strictly needed. I can remove it.
>>
>>>>>> eh = (struct ethhdr *)(txp->data);
>>>>>> type = ntohs(eh->h_proto);
>>>>>>
>>>>>> @@ -553,6 +556,7 @@ void brcmf_txfinalize(struct brcmf_if *ifp, struct
>>>>>> sk_buff *txp, bool success)
>>>>>> if (!success)
>>>>>> ifp->stats.tx_errors++;
>>>>>>
>>>>>> +free:
>>>>>> brcmu_pkt_buf_free_skb(txp);
>>>>>> }
>>>>>>
>>>>>> diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fwsignal.c
>>>>>> b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fwsignal.c
>>>>>> index f82c9ab..98cb83f 100644
>>>>>> --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fwsignal.c
>>>>>> +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fwsignal.c
>>>>>> @@ -1899,8 +1899,10 @@ int brcmf_fws_process_skb(struct brcmf_if *ifp,
>>>>>> struct sk_buff *skb)
>>>>>>
>>>>>> if (fws->avoid_queueing) {
>>>>>> rc = brcmf_proto_txdata(drvr, ifp->ifidx, 0, skb);
>>>>>> - if (rc < 0)
>>>>>> + if (rc < 0) {
>>>>>> + (void)brcmf_proto_hdrpull(drvr, false, skb,
>>>>>> &ifp);
>>>
>>> Could it be that the ifp is NULL pointer after brcmf_proto_hdrpull().
>>> Can you check. Better use tmp_ifp variable in this call as you have a
>>> valid ifp before this call for sure.
>>>
>> To be on the safe side I can use NULL as in param like you propose,
>> and use the available ifp.
>>
>>>>>> brcmf_txfinalize(ifp, skb, false);
>>>>>> + }
>>>>>> return rc;
>>>>>> }
>>>>>>
>>>>>> diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c
>>>>>> b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c
>>>>>> index a14d9d9d..485e2ad 100644
>>>>>> --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c
>>>>>> +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c
>>>>>> @@ -2721,7 +2721,7 @@ static int brcmf_sdio_bus_txdata(struct device
>>>>>> *dev, struct sk_buff *pkt)
>>>>>> *(u16 *)(pkt->cb) = 0;
>>>>>> if (!brcmf_sdio_prec_enq(&bus->txq, pkt, prec)) {
>>>>>> skb_pull(pkt, bus->tx_hdrlen);
>>>>>> - brcmf_err("out of bus->txq !!!\n");
>>>>>> + brcmf_dbg(INFO, "out of bus->txq !!!\n");
>>>
>>> Now that I understand the issue I want to keep this as error print as it
>>> should be very unlikely.
>> I would like to test this patch with the watermark fix to confirm this.
>
> Can you try this?
>
> Regards,
> Arend
>
> ---
> diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fwsignal.c
> b/drive
> index cd221ab..9f9024a 100644
> --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fwsignal.c
> +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fwsignal.c
> @@ -2469,10 +2469,22 @@ void brcmf_fws_bustxfail(struct brcmf_fws_info
> *fws, str
> void brcmf_fws_bus_blocked(struct brcmf_pub *drvr, bool flow_blocked)
> {
> struct brcmf_fws_info *fws = drvr->fws;
> + struct brcmf_if *ifp;
> + int i;
>
> - fws->bus_flow_blocked = flow_blocked;
> - if (!flow_blocked)
> - brcmf_fws_schedule_deq(fws);
> - else
> - fws->stats.bus_flow_block++;
> + if (fws->avoid_queueing) {
> + for (i = 0; i < BRCMF_MAX_IFS; i++) {
> + ifp = drvr->iflist[i];
> + if (!ifp || !ifp->ndev)
> + continue;
> + brcmf_txflowblock_if(ifp,
> BRCMF_NETIF_STOP_REASON_FLOW,
> + flow_blocked);
> + }
> + } else {
> + fws->bus_flow_blocked = flow_blocked;
> + if (!flow_blocked)
> + brcmf_fws_schedule_deq(fws);
> + else
> + fws->stats.bus_flow_block++;
> + }
> }
>
Thanks for the code. I run a quick test and it looks fine.
I added some prints to check the progress:
len - is number of items in the queue
max - is max number of entries in the queue
[ 89.407856] [brcmf_sdio_prec_enq] prec 2 prio 0 len 1789 max 2048
[ 89.414682] [brcmf_sdio_prec_enq] prec 2 prio 0 len 1790 max 2048
[ 89.421497] [brcmf_sdio_prec_enq] prec 2 prio 0 len 1791 max 2048
[ 93.970466] [brcmf_sdio_prec_enq] prec 2 prio 0 len 1524 max 2048
[ 93.977520] [brcmf_sdio_prec_enq] prec 2 prio 0 len 1525 max 2048
[ 93.984572] [brcmf_sdio_prec_enq] prec 2 prio 0 len 1526 max 2048
I will some run more WLAN tests tomorrow to make sure.
When I'm done testing I will update my patch as well and let you know.
I came across this issue when I tried to connect to my WLAN access
point. The bug was triggered due to a lot of background traffic
(broadcast and multicast) in the network filling up the queue.
It's now fixed so that the queue is not flooded. Now I move on to the
next issue. It's still difficult to connect because the background
eats up all the bandwidth (this is not a constant issue but it happens
from time to time depending on the background load).
For queueing-mode there seems to exist logic for handling multicast
traffic separately but for the SDIO case (no-queueing) normal traffic
gets same precedence as multicast traffic.
I'm considering something like this:
--- a/drivers/net/wireless/brcm80211/brcmfmac/fwsignal.c
+++ b/drivers/net/wireless/brcm80211/brcmfmac/fwsignal.c
@@ -1900,6 +1902,8 @@ int brcmf_fws_process_skb(struct brcmf_if *ifp,
struct sk_buff *skb)
drvr->tx_multicast += !!multicast;
if (fws->avoid_queueing) {
+ if (multicast)
+ skb->priority = PRIO_8021D_NONE;
rc = brcmf_proto_txdata(drvr, ifp->ifidx, 0, skb);
if (rc < 0) {
(void)brcmf_proto_hdrpull(drvr, false, skb, NULL);
It feels a little hacky.
I would like to use the drvr->tx_multicast instead, if possible.
The problem is that the "drvr" struct is not passed down to the sdio layer.
One could update bcdc.c : brcmf_proto_bcdc_txdata() to pass
"drcr->multicast" to the SDIO layer but not all bus implementations
need this information (USB for instance)
Any suggestions?
BR
Per Forlin
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