| From 92caaf40a058d4eac8061c0e3240f0b23aba69ce Mon Sep 17 00:00:00 2001 |
| From: Michael-CY Lee <michael-cy.lee@mediatek.com> |
| Date: Thu, 24 Aug 2023 10:04:15 +0800 |
| Subject: hostapd: mtk: refactor the flow to create Wide Bandwidth |
| Channel Switch IE |
| |
| This patch changes the flow to create Wide Bandwidth Channel Switch IE: |
| 1. 2 GHz: Wide Bandwidth Channel Switch IE should not present. |
| 2. 5 GHz: fill the subfields according to VHT operation. |
| 3. 6 GHz: fill the subfields according to VHT operation and HE operation |
| in HE mode and EHT mode, respectively. |
| This is because the definition of the subfields of Wide Bandwidth |
| Channel Switch IE is ambiguous: |
| 1. 802.11ac: the definition of subfields follows VHT operation |
| (IEEE80211-2020 9.4.2.160) |
| 2. 802.11ax: the definition of subfields is not specified |
| 3. 802.11be: the definition of subfields follows VHT operation in 5 |
| GHz and HE operation in 6 GHz (IEEE P802.11be D3.2 9.4.2.159) |
| |
| To support 320 MHz |
| channel switch, set width to 4 |
| |
| Signed-off-by: Michael-CY Lee <michael-cy.lee@mediatek.com> |
| --- |
| src/ap/ieee802_11.c | 99 ++++++++++++++++++++++++++++++++++----------- |
| 1 file changed, 76 insertions(+), 23 deletions(-) |
| |
| diff --git a/src/ap/ieee802_11.c b/src/ap/ieee802_11.c |
| index ef520c8..5f4d78f 100755 |
| --- a/src/ap/ieee802_11.c |
| +++ b/src/ap/ieee802_11.c |
| @@ -7065,57 +7065,110 @@ u8 * hostapd_eid_txpower_envelope(struct hostapd_data *hapd, u8 *eid) |
| |
| u8 * hostapd_eid_wb_chsw_wrapper(struct hostapd_data *hapd, u8 *eid) |
| { |
| - u8 bw, chan1, chan2 = 0; |
| - int freq1; |
| + u8 new_bw_field, ccfs0_chan, ccfs1_chan = 0; |
| + int ccfs0_freq = 0, ccfs1_freq = 0; |
| + int control_freq, center_freq1, center_freq2, bandwidth; |
| + int base_freq, offset; |
| + bool is_6ghz, use_he_oper; |
| |
| if (!hapd->cs_freq_params.channel || |
| + hapd->cs_freq_params.bandwidth == 20 || |
| (!hapd->cs_freq_params.vht_enabled && |
| !hapd->cs_freq_params.he_enabled && |
| !hapd->cs_freq_params.eht_enabled)) |
| return eid; |
| |
| - /* bandwidth: 0: 40, 1: 80, 2: 160, 3: 80+80, 4: 320 */ |
| - switch (hapd->cs_freq_params.bandwidth) { |
| + control_freq = hapd->cs_freq_params.freq; |
| + center_freq1 = hapd->cs_freq_params.center_freq1; |
| + center_freq2 = hapd->cs_freq_params.center_freq2; |
| + bandwidth = hapd->cs_freq_params.bandwidth; |
| + |
| + /* center_freq2 is used if and only if bandwidth is |
| + * 80+80 MHz and phy mode is not EHT |
| + */ |
| + if (center_freq2 && |
| + (bandwidth != 80 || hapd->cs_freq_params.eht_enabled)) |
| + return eid; |
| + |
| + is_6ghz = is_6ghz_freq(control_freq); |
| + use_he_oper = is_6ghz && hapd->cs_freq_params.eht_enabled; |
| + base_freq = is_6ghz ? 5955 : 5180; |
| + |
| + /* About the subfields of the Wide Bandwidth Channel Switch IE, |
| + * IEEE802.11-2020 9.4.2.160 specifies that the subfields New |
| + * Channel Width, New Channel Center Frequency Segment 0 and New |
| + * Channel Center Frequency Segment 1 have the same definition as |
| + * they are in the VHT operation information field. |
| + * However, the standard does not specify the definition of these |
| + * subfields when it comes to HE phy-mode in 6 GHz. |
| + * And in IEEE P802.11be D3.2 9.4.2.159, it specifies that the |
| + * defition should follow VHT operation in 5 GHz, and follow HE |
| + * oepration in 6 GHz. |
| + * Problem happens here for some HE STAs in 6 GHz, they might still |
| + * use VHT operation to parse these subfields. |
| + * |
| + * Here we follow the new Standard to build the IE, meanwhile we have |
| + * a workaround for HE mode in 6 GHz. |
| + * |
| + * 5 GHz: VHT operation |
| + * HE mode in 6 GHz: VHT operation |
| + * EHT mode in 6 GHz: HE operation |
| + */ |
| + ccfs0_freq = center_freq1; |
| + ccfs1_freq = center_freq2; |
| + switch (bandwidth) { |
| case 40: |
| - bw = 0; |
| + new_bw_field = use_he_oper ? 1 : 0; |
| break; |
| case 80: |
| - /* check if it's 80+80 */ |
| - if (!hapd->cs_freq_params.center_freq2) |
| - bw = 1; |
| + if (ccfs1_freq) |
| + new_bw_field = use_he_oper ? 3 : 1; |
| else |
| - bw = 3; |
| + new_bw_field = use_he_oper ? 2 : 1; |
| break; |
| case 160: |
| - bw = 2; |
| + new_bw_field = use_he_oper ? 3 : 1; |
| + |
| + /* ccfs0 is primary 80 MHz |
| + * ccfs1 is center frequency |
| + */ |
| + offset = (control_freq - base_freq) / 20; |
| + ccfs0_freq = control_freq + 30 - (offset & 3) * 20; |
| + ccfs1_freq = center_freq1; |
| break; |
| case 320: |
| - bw = 4; |
| + /* TODO switch to bandwidth 320 MHz should be |
| + * indicated by Bandwidth indication IE. |
| + */ |
| + new_bw_field = 4; |
| + |
| + /* ccfs0 is primary 160 MHz |
| + * ccfs1 is center frequency |
| + */ |
| + offset = (control_freq - base_freq) / 20; |
| + ccfs0_freq = control_freq + 70 - (offset & 7) * 20; |
| + ccfs1_freq = center_freq1; |
| break; |
| default: |
| - /* not valid VHT bandwidth or not in CSA */ |
| + /* not a valid VHT/HE bandwidth or not in CSA */ |
| return eid; |
| } |
| |
| - freq1 = hapd->cs_freq_params.center_freq1 ? |
| - hapd->cs_freq_params.center_freq1 : |
| - hapd->cs_freq_params.freq; |
| - if (ieee80211_freq_to_chan(freq1, &chan1) != |
| - HOSTAPD_MODE_IEEE80211A) |
| + if (ieee80211_freq_to_chan(ccfs0_freq, &ccfs0_chan) != |
| + HOSTAPD_MODE_IEEE80211A) |
| return eid; |
| |
| - if (hapd->cs_freq_params.center_freq2 && |
| - ieee80211_freq_to_chan(hapd->cs_freq_params.center_freq2, |
| - &chan2) != HOSTAPD_MODE_IEEE80211A) |
| + if (ccfs1_freq && ieee80211_freq_to_chan(ccfs1_freq, &ccfs1_chan) != |
| + HOSTAPD_MODE_IEEE80211A) |
| return eid; |
| |
| *eid++ = WLAN_EID_CHANNEL_SWITCH_WRAPPER; |
| *eid++ = 5; /* Length of Channel Switch Wrapper */ |
| *eid++ = WLAN_EID_WIDE_BW_CHSWITCH; |
| *eid++ = 3; /* Length of Wide Bandwidth Channel Switch element */ |
| - *eid++ = bw; /* New Channel Width */ |
| - *eid++ = chan1; /* New Channel Center Frequency Segment 0 */ |
| - *eid++ = chan2; /* New Channel Center Frequency Segment 1 */ |
| + *eid++ = new_bw_field; /* New Channel Width */ |
| + *eid++ = ccfs0_chan; /* New Channel Center Frequency Segment 0 */ |
| + *eid++ = ccfs1_chan; /* New Channel Center Frequency Segment 1 */ |
| |
| return eid; |
| } |
| -- |
| 2.25.1 |
| |