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Message-ID: <5b41f1ae-72e7-6b7a-2459-b736399a1c40@gmail.com>
Date:   Thu, 1 Dec 2022 16:15:08 +0200
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Subject: [PATCH v4 2/3] wifi: rtl8xxxu: Fix the channel width reporting
Content-Language: en-US
From:   Bitterblue Smith <rtl8821cerfe2@gmail.com>
To:     "linux-wireless@vger.kernel.org" <linux-wireless@vger.kernel.org>
Cc:     Jes Sorensen <Jes.Sorensen@gmail.com>,
        Ping-Ke Shih <pkshih@realtek.com>
References: <1a270918-da22-ff5f-29fc-7855f740c5ba@gmail.com>
In-Reply-To: <1a270918-da22-ff5f-29fc-7855f740c5ba@gmail.com>
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Precedence: bulk

The gen 2 chips RTL8192EU and RTL8188FU periodically send the driver
reports about the TX rate, and the driver passes these reports to
sta_statistics. The reports from RTL8192EU may or may not include the
channel width. The reports from RTL8188FU do not include it.

Only access the c2h->ra_report.bw field if the report (skb) is big
enough.

The other problem fixed here is that the code was actually never
changing the channel width initially reported by
rtl8xxxu_bss_info_changed because the value of RATE_INFO_BW_20 is 0.

Fixes: 0985d3a410ac ("rtl8xxxu: Feed current txrate information for mac80211")
Signed-off-by: Bitterblue Smith <rtl8821cerfe2@gmail.com>
---
v4:
 - Use the more convenient offsetofend macro.
 
v3:
 - Don't assume bw will always be 1 byte.
 
v2:
 - Eliminate the magic numbers.
---
 drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
index 28f136064297..7ca46fb77a3b 100644
--- a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
+++ b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
@@ -5569,7 +5569,6 @@ static void rtl8xxxu_c2hcmd_callback(struct work_struct *work)
 			rarpt->txrate.flags = 0;
 			rate = c2h->ra_report.rate;
 			sgi = c2h->ra_report.sgi;
-			bw = c2h->ra_report.bw;
 
 			if (rate < DESC_RATE_MCS0) {
 				rarpt->txrate.legacy =
@@ -5586,8 +5585,13 @@ static void rtl8xxxu_c2hcmd_callback(struct work_struct *work)
 						RATE_INFO_FLAGS_SHORT_GI;
 				}
 
-				if (bw == RATE_INFO_BW_20)
-					rarpt->txrate.bw |= RATE_INFO_BW_20;
+				if (skb->len >= offsetofend(typeof(*c2h), ra_report.bw)) {
+					if (c2h->ra_report.bw == RTL8XXXU_CHANNEL_WIDTH_40)
+						bw = RATE_INFO_BW_40;
+					else
+						bw = RATE_INFO_BW_20;
+					rarpt->txrate.bw = bw;
+				}
 			}
 			bit_rate = cfg80211_calculate_bitrate(&rarpt->txrate);
 			rarpt->bit_rate = bit_rate;
-- 
2.38.0