From: Bitterblue Smith Date: Wed, 29 Apr 2026 12:02:48 +0000 (+0300) Subject: wifi: rtl8xxxu: Detect the maximum supported channel width X-Git-Url: http://git.ipfire.org/gitweb/index.cgi?a=commitdiff_plain;h=ef771eabc79d5f21b63689cca0e0fa5493fa0a8a;p=thirdparty%2Flinux.git wifi: rtl8xxxu: Detect the maximum supported channel width Some devices malfunction when connected to a network with 40 MHz channel width, because they don't support that. RTL8188FU, RTL8192FU, and RTL8710BU (RTL8188GU) have a way to signal this (and some other capabilities) to the driver. Get this information from the hardware and advertise 40 MHz support only when the hardware can handle it. We assume the other chips can always handle it. RTL8710BU needs a different way to retrieve this information, which will be implemented some other time. Fixes: dbf9b7bb0edf ("wifi: rtl8xxxu: Enable 40 MHz width by default") Cc: stable@vger.kernel.org Closes: https://bugzilla.kernel.org/show_bug.cgi?id=221394 Signed-off-by: Bitterblue Smith Reviewed-by: Ping-Ke Shih Signed-off-by: Ping-Ke Shih Link: https://patch.msgid.link/c57de68e-5d57-4c26-898f-8a284bb25381@gmail.com --- diff --git a/drivers/net/wireless/realtek/rtl8xxxu/8188e.c b/drivers/net/wireless/realtek/rtl8xxxu/8188e.c index 766a7a7c7d281..fea5aec9ced99 100644 --- a/drivers/net/wireless/realtek/rtl8xxxu/8188e.c +++ b/drivers/net/wireless/realtek/rtl8xxxu/8188e.c @@ -1866,6 +1866,7 @@ struct rtl8xxxu_fileops rtl8188eu_fops = { .has_tx_report = 1, .init_reg_pkt_life_time = 1, .gen2_thermal_meter = 1, + .hw_feature_report = 0, .max_sec_cam_num = 32, .adda_1t_init = 0x0b1b25a0, .adda_1t_path_on = 0x0bdb25a0, diff --git a/drivers/net/wireless/realtek/rtl8xxxu/8188f.c b/drivers/net/wireless/realtek/rtl8xxxu/8188f.c index 3abf14d7044f3..5556aad1a7ad3 100644 --- a/drivers/net/wireless/realtek/rtl8xxxu/8188f.c +++ b/drivers/net/wireless/realtek/rtl8xxxu/8188f.c @@ -1745,6 +1745,7 @@ struct rtl8xxxu_fileops rtl8188fu_fops = { .init_reg_rxfltmap = 1, .init_reg_pkt_life_time = 1, .init_reg_hmtfr = 1, + .hw_feature_report = 1, .ampdu_max_time = 0x70, .ustime_tsf_edca = 0x28, .max_aggr_num = 0x0c14, diff --git a/drivers/net/wireless/realtek/rtl8xxxu/8192c.c b/drivers/net/wireless/realtek/rtl8xxxu/8192c.c index 444872131c663..508322a8f3108 100644 --- a/drivers/net/wireless/realtek/rtl8xxxu/8192c.c +++ b/drivers/net/wireless/realtek/rtl8xxxu/8192c.c @@ -723,6 +723,7 @@ struct rtl8xxxu_fileops rtl8192cu_fops = { .tx_desc_size = sizeof(struct rtl8xxxu_txdesc32), .rx_desc_size = sizeof(struct rtl8xxxu_rxdesc16), .supports_ap = 1, + .hw_feature_report = 0, .max_macid_num = 32, .max_sec_cam_num = 32, .adda_1t_init = 0x0b1b25a0, diff --git a/drivers/net/wireless/realtek/rtl8xxxu/8192e.c b/drivers/net/wireless/realtek/rtl8xxxu/8192e.c index 8e123bbfc6659..690ace3031503 100644 --- a/drivers/net/wireless/realtek/rtl8xxxu/8192e.c +++ b/drivers/net/wireless/realtek/rtl8xxxu/8192e.c @@ -1751,6 +1751,7 @@ struct rtl8xxxu_fileops rtl8192eu_fops = { .has_s0s1 = 0, .gen2_thermal_meter = 1, .needs_full_init = 1, + .hw_feature_report = 0, .supports_ap = 1, .max_macid_num = 128, .max_sec_cam_num = 64, diff --git a/drivers/net/wireless/realtek/rtl8xxxu/8192f.c b/drivers/net/wireless/realtek/rtl8xxxu/8192f.c index cd2156b7a57ab..5f076da4b5506 100644 --- a/drivers/net/wireless/realtek/rtl8xxxu/8192f.c +++ b/drivers/net/wireless/realtek/rtl8xxxu/8192f.c @@ -2074,6 +2074,7 @@ struct rtl8xxxu_fileops rtl8192fu_fops = { .init_reg_rxfltmap = 1, .init_reg_pkt_life_time = 1, .init_reg_hmtfr = 1, + .hw_feature_report = 1, .ampdu_max_time = 0x5e, .ustime_tsf_edca = 0x50, .max_aggr_num = 0x1f1f, diff --git a/drivers/net/wireless/realtek/rtl8xxxu/8710b.c b/drivers/net/wireless/realtek/rtl8xxxu/8710b.c index 11c63c320eaeb..a87e692bfc812 100644 --- a/drivers/net/wireless/realtek/rtl8xxxu/8710b.c +++ b/drivers/net/wireless/realtek/rtl8xxxu/8710b.c @@ -1852,6 +1852,7 @@ struct rtl8xxxu_fileops rtl8710bu_fops = { .init_reg_rxfltmap = 1, .init_reg_pkt_life_time = 1, .init_reg_hmtfr = 1, + .hw_feature_report = 0, /* TODO, it's different */ .ampdu_max_time = 0x5e, /* * The RTL8710BU vendor driver uses 0x50 here and it works fine, diff --git a/drivers/net/wireless/realtek/rtl8xxxu/8723a.c b/drivers/net/wireless/realtek/rtl8xxxu/8723a.c index 4f4493d0bfc2d..18e038b82f490 100644 --- a/drivers/net/wireless/realtek/rtl8xxxu/8723a.c +++ b/drivers/net/wireless/realtek/rtl8xxxu/8723a.c @@ -632,6 +632,7 @@ struct rtl8xxxu_fileops rtl8723au_fops = { .rx_agg_buf_size = 16000, .tx_desc_size = sizeof(struct rtl8xxxu_txdesc32), .rx_desc_size = sizeof(struct rtl8xxxu_rxdesc16), + .hw_feature_report = 0, .max_sec_cam_num = 32, .adda_1t_init = 0x0b1b25a0, .adda_1t_path_on = 0x0bdb25a0, diff --git a/drivers/net/wireless/realtek/rtl8xxxu/8723b.c b/drivers/net/wireless/realtek/rtl8xxxu/8723b.c index cc2e60b06f647..e314ef991b388 100644 --- a/drivers/net/wireless/realtek/rtl8xxxu/8723b.c +++ b/drivers/net/wireless/realtek/rtl8xxxu/8723b.c @@ -1746,6 +1746,7 @@ struct rtl8xxxu_fileops rtl8723bu_fops = { .gen2_thermal_meter = 1, .needs_full_init = 1, .init_reg_hmtfr = 1, + .hw_feature_report = 0, .ampdu_max_time = 0x5e, .ustime_tsf_edca = 0x50, .max_aggr_num = 0x0c14, diff --git a/drivers/net/wireless/realtek/rtl8xxxu/core.c b/drivers/net/wireless/realtek/rtl8xxxu/core.c index 508137e4a87aa..646fe76b086e7 100644 --- a/drivers/net/wireless/realtek/rtl8xxxu/core.c +++ b/drivers/net/wireless/realtek/rtl8xxxu/core.c @@ -14,6 +14,7 @@ */ #include +#include #include "regs.h" #include "rtl8xxxu.h" @@ -3915,6 +3916,46 @@ static inline u8 rtl8xxxu_get_macid(struct rtl8xxxu_priv *priv, return sta_info->macid; } +static void rtl8xxxu_request_hw_feature(struct rtl8xxxu_priv *priv) +{ + if (!priv->fops->hw_feature_report) + return; + + rtl8xxxu_write8(priv, REG_C2HEVT_MSG_NORMAL, C2H_HW_FEATURE_DUMP); +} + +static int rtl8xxxu_dump_hw_feature(struct rtl8xxxu_priv *priv) +{ + static const u8 bw_map[8] = { 0, 0, 160, 5, 10, 20, 40, 80 }; + struct rtl8xxxu_hw_feature *hw_feature = &priv->hw_feature; + u8 feature[13]; + int i, ret; + u8 id, bw; + + if (!priv->fops->hw_feature_report) { + hw_feature->max_bw = 40; + return 0; + } + + ret = read_poll_timeout(rtl8xxxu_read8, id, + id == C2H_HW_FEATURE_REPORT, + 10000, 800000, false, + priv, REG_C2HEVT_MSG_NORMAL); + if (ret) + return ret; + + for (i = 0; i < ARRAY_SIZE(feature); i++) + feature[i] = rtl8xxxu_read8(priv, REG_C2HEVT_MSG_NORMAL + 2 + i); + + rtl8xxxu_write8(priv, REG_C2HEVT_MSG_NORMAL, 0); + + bw = u8_get_bits(feature[6], GENMASK(2, 0)); + + hw_feature->max_bw = bw_map[bw]; + + return 0; +} + static int rtl8xxxu_init_device(struct ieee80211_hw *hw) { struct rtl8xxxu_priv *priv = hw->priv; @@ -3961,6 +4002,8 @@ static int rtl8xxxu_init_device(struct ieee80211_hw *hw) */ rtl8xxxu_write16(priv, REG_TRXFF_BNDY + 2, fops->trxff_boundary); + rtl8xxxu_request_hw_feature(priv); + for (int retry = 5; retry >= 0 ; retry--) { ret = rtl8xxxu_download_firmware(priv); dev_dbg(dev, "%s: download_firmware %i\n", __func__, ret); @@ -3976,6 +4019,12 @@ static int rtl8xxxu_init_device(struct ieee80211_hw *hw) if (ret) goto exit; + ret = rtl8xxxu_dump_hw_feature(priv); + if (ret) { + dev_err(dev, "failed to dump hw feature\n"); + goto exit; + } + if (fops->phy_init_antenna_selection) fops->phy_init_antenna_selection(priv); @@ -7844,15 +7893,20 @@ static int rtl8xxxu_probe(struct usb_interface *interface, sband->ht_cap.ht_supported = true; sband->ht_cap.ampdu_factor = IEEE80211_HT_MAX_AMPDU_64K; sband->ht_cap.ampdu_density = IEEE80211_HT_MPDU_DENSITY_16; - sband->ht_cap.cap = IEEE80211_HT_CAP_SGI_20 | IEEE80211_HT_CAP_SGI_40 | - IEEE80211_HT_CAP_SUP_WIDTH_20_40; + sband->ht_cap.cap = IEEE80211_HT_CAP_SGI_20; + + if (priv->hw_feature.max_bw >= 40) { + sband->ht_cap.cap |= IEEE80211_HT_CAP_SGI_40; + sband->ht_cap.cap |= IEEE80211_HT_CAP_SUP_WIDTH_20_40; + } else { + dev_info(&udev->dev, "hardware doesn't support HT40\n"); + } + memset(&sband->ht_cap.mcs, 0, sizeof(sband->ht_cap.mcs)); sband->ht_cap.mcs.rx_mask[0] = 0xff; sband->ht_cap.mcs.rx_mask[4] = 0x01; - if (priv->rf_paths > 1) { + if (priv->rf_paths > 1) sband->ht_cap.mcs.rx_mask[1] = 0xff; - sband->ht_cap.cap |= IEEE80211_HT_CAP_SGI_40; - } sband->ht_cap.mcs.tx_params = IEEE80211_HT_MCS_TX_DEFINED; hw->wiphy->bands[NL80211_BAND_2GHZ] = sband; diff --git a/drivers/net/wireless/realtek/rtl8xxxu/regs.h b/drivers/net/wireless/realtek/rtl8xxxu/regs.h index 0741db8d08bff..eafaef1438b97 100644 --- a/drivers/net/wireless/realtek/rtl8xxxu/regs.h +++ b/drivers/net/wireless/realtek/rtl8xxxu/regs.h @@ -447,6 +447,8 @@ /* 8188EU */ #define REG_32K_CTRL 0x0194 #define REG_C2HEVT_MSG_NORMAL 0x01a0 +#define C2H_HW_FEATURE_REPORT 0x19 +#define C2H_HW_FEATURE_DUMP 0xfd /* 8192EU/8723BU/8812 */ #define REG_C2HEVT_CMD_ID_8723B 0x01ae #define REG_C2HEVT_CLEAR 0x01af diff --git a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu.h b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu.h index 9fb2583ffffc3..eeb18eb0e4c0f 100644 --- a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu.h +++ b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu.h @@ -1789,11 +1789,17 @@ struct rtl8xxxu_cfo_tracking { #define RTL8XXXU_BC_MC_MACID1 1 #define RTL8XXXU_MAX_SEC_CAM_NUM 64 +struct rtl8xxxu_hw_feature { + u8 max_bw; +}; + struct rtl8xxxu_priv { struct ieee80211_hw *hw; struct usb_device *udev; struct rtl8xxxu_fileops *fops; + struct rtl8xxxu_hw_feature hw_feature; + spinlock_t tx_urb_lock; struct list_head tx_urb_free_list; int tx_urb_free_count; @@ -2009,6 +2015,7 @@ struct rtl8xxxu_fileops { u8 init_reg_pkt_life_time:1; u8 init_reg_hmtfr:1; u8 supports_concurrent:1; + u8 hw_feature_report:1; u8 ampdu_max_time; u8 ustime_tsf_edca; u16 max_aggr_num;