> -----Original Message-----
> From: Bitterblue Smith <rtl8821cerfe2@xxxxxxxxx>
> Sent: Tuesday, November 29, 2022 3:30 AM
> To: linux-wireless@xxxxxxxxxxxxxxx
> Cc: Jes Sorensen <Jes.Sorensen@xxxxxxxxx>; Ping-Ke Shih <pkshih@xxxxxxxxxxx>
> Subject: [PATCH v2 2/3] wifi: rtl8xxxu: Fix the channel width reporting
>
> 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@xxxxxxxxx>
> ---
> v2:
> - Eliminate the magic numbers.
> ---
> drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu.h | 2 ++
> drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c | 11 ++++++++---
> 2 files changed, 10 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu.h
> b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu.h
> index d26df4095da0..9be53e0f25cc 100644
> --- a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu.h
> +++ b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu.h
> @@ -1187,6 +1187,8 @@ enum rtl8xxxu_bw_mode {
> RTL8XXXU_CHANNEL_WIDTH_MAX = 5,
> };
>
> +#define RTL8XXXU_C2H_HDR_LEN 2 /* id and seq */
> +
> struct rtl8723bu_c2h {
> u8 id;
> u8 seq;
> diff --git a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
> b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
> index 28f136064297..352779fe4b78 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 +5585,14 @@ 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 > RTL8XXXU_C2H_HDR_LEN +
> + offsetof(typeof(c2h->ra_report), bw)) {
I think this is not very intuitive, because this logic is correct only if 'bw' is u8.
Then, this option may be not bad:
if (skb->len >= RTL8XXXU_C2H_HDR_LEN + offsetof(typeof(c2h->ra_report), bw) + sizeof(c2h->ra_report.bw))
or
Not need RTL8XXXU_C2H_HDR_LEN. Just use offsetof() to calculate:
if (skb->len >= offsetof(typeof(*c2h), ra_report.bw) + sizeof(c2h->ra_report.bw))
or
If you still prefer 'skb->len >', this may be more concise than original one.
if (skb->len > offsetof(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
>
> ------Please consider the environment before printing this e-mail.
