From: Bitterblue Smith <rtl8821cerfe2@gmail.com>
To: Ping-Ke Shih <pkshih@realtek.com>,
"linux-wireless@vger.kernel.org" <linux-wireless@vger.kernel.org>
Cc: Sascha Hauer <sha@pengutronix.de>,
Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Subject: Re: [PATCH] wifi: rtw88: usb: Fix disconnection after beacon loss
Date: Tue, 30 Apr 2024 15:14:28 +0300 [thread overview]
Message-ID: <cae2d330-a4fb-4570-9dde-09684af23ffd@gmail.com> (raw)
In-Reply-To: <5b2e95cdac3d400eb2c9ef2eb20dc221@realtek.com>
On 30/04/2024 03:50, Ping-Ke Shih wrote:
> +Cc: Martin for rtw88 SDIO that seems have the same problem
>
> Bitterblue Smith <rtl8821cerfe2@gmail.com> wrote:
>> When there is beacon loss, for example due to unrelated Bluetooth
>> devices transmitting music nearby, the wifi connection dies soon
>> after the first beacon loss message:
>>
>> Apr 28 20:47:14 ideapad2 wpa_supplicant[1161]: wlp3s0f3u4:
>> CTRL-EVENT-BEACON-LOSS
>> Apr 28 20:47:15 ideapad2 wpa_supplicant[1161]: wlp3s0f3u4:
>> CTRL-EVENT-DISCONNECTED bssid=... reason=4 locally_generated=1
>>
>> Apr 28 20:47:24 ideapad2 wpa_supplicant[1161]: wlp3s0f3u4:
>> CTRL-EVENT-BEACON-LOSS
>> Apr 28 20:47:25 ideapad2 wpa_supplicant[1161]: wlp3s0f3u4:
>> CTRL-EVENT-DISCONNECTED bssid=... reason=4 locally_generated=1
>>
>> Apr 28 20:47:34 ideapad2 wpa_supplicant[1161]: wlp3s0f3u4:
>> CTRL-EVENT-BEACON-LOSS
>> Apr 28 20:47:35 ideapad2 wpa_supplicant[1161]: wlp3s0f3u4:
>> CTRL-EVENT-DISCONNECTED bssid=... reason=4 locally_generated=1
>>
>> When the beacon loss happens, mac80211 makes rtw88 transmit a QOS
>> NULL frame and asks to confirm the ACK status. Even though rtw88
>> confirms to mac80211 that the QOS NULL was transmitted successfully,
>> the connection still dies. This is because rtw88 is handing the QOS
>> NULL back to mac80211 with skb->data pointing to the headroom (the
>> TX descriptor) instead of ieee80211_hdr.
>>
>> Fix the disconnection by moving skb->data to the correct position
>> before ieee80211_tx_status_irqsafe().
>>
>> The problem was observed with RTL8811AU (TP-Link Archer T2U Nano)
>> and the potential future rtw88_8821au driver. Also tested with
>> RTL8811CU (Tenda U9).
>>
>> Cc: stable@vger.kernel.org
>> Signed-off-by: Bitterblue Smith <rtl8821cerfe2@gmail.com>
>> ---
>> drivers/net/wireless/realtek/rtw88/usb.c | 2 ++
>> 1 file changed, 2 insertions(+)
>>
>> diff --git a/drivers/net/wireless/realtek/rtw88/usb.c b/drivers/net/wireless/realtek/rtw88/usb.c
>> index 3ba7b81c6080..1dfe7c6ae4ba 100644
>> --- a/drivers/net/wireless/realtek/rtw88/usb.c
>> +++ b/drivers/net/wireless/realtek/rtw88/usb.c
>> @@ -278,6 +278,8 @@ static void rtw_usb_write_port_tx_complete(struct urb *urb)
>> info = IEEE80211_SKB_CB(skb);
>> tx_data = rtw_usb_get_tx_data(skb);
>>
>> + skb_pull(skb, rtwdev->chip->tx_pkt_desc_sz);
>> +
>
> There are two cases of arguments of skb_push() for USB:
> 1. skb_push(skb, chip->tx_pkt_desc_sz);
> 2. skb_push(skb, headsize);
> headsize = pkt_info->offset ? pkt_info->offset : desclen;
> pkt_info->offset = chip->tx_pkt_desc_sz;
> desclen = chip->tx_pkt_desc_sz;
>
> Eventually all are chip->tx_pkt_desc_sz, but spend a little time to ensure this.
> Could you test and have another patch to change above case (2) to (1)?
>
I see what you mean. I will make it another patch, because
the skb from case 2 is not sent to mac80211.
>> /* enqueue to wait for tx report */
>> if (info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS) {
>> rtw_tx_report_enqueue(rtwdev, skb, tx_data->sn);
>> --
>> 2.44.0
>
next prev parent reply other threads:[~2024-04-30 12:14 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-29 17:57 [PATCH] wifi: rtw88: usb: Fix disconnection after beacon loss Bitterblue Smith
2024-04-30 0:50 ` Ping-Ke Shih
2024-04-30 12:14 ` Bitterblue Smith [this message]
2024-05-09 6:23 ` Ping-Ke Shih
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