[PATCH ath-next 3/3] wifi: ath11k: add a module parameter to select the hardware mode

[Julius Bairaktaris <julius@bairaktaris.de>]

ath11k always uses the highest priority hardware mode the firmware
advertises. On the Zyxel NBG7815 that is DBS+SBS, which splits the
eight 5 GHz chains between two radios, neither with a 160 MHz channel
width. The firmware also advertises DBS, which gives one 5 GHz radio
with all eight chains and 160 MHz. Add a hw_mode parameter that selects
any mode the firmware advertises; for a mode it does not advertise, warn
with the modes it does advertise and keep the default.

On the NBG7815, hw_mode=1 brings up the 8-chain 5 GHz radio. iperf3
from the router to a 2x2 HE client with 4 streams gave 1.22 and
1.20 Gbit/s at 160 MHz (two 20 s runs), against 886 Mbit/s at 80 MHz
with the unpatched driver (one run).

Tested-on: IPQ8074 hw2.0 AHB WLAN.HK.2.9.0.1-02146-QCAHKSWPL_SILICONZ-1

Tested-by: Semih Baskan <strst.gs@gmail.com>
Signed-off-by: Julius Bairaktaris <julius@bairaktaris.de>
---
 drivers/net/wireless/ath/ath11k/core.c |  6 ++++++
 drivers/net/wireless/ath/ath11k/core.h |  1 +
 drivers/net/wireless/ath/ath11k/wmi.c  | 17 +++++++++++++++--
 3 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/ath/ath11k/core.c b/drivers/net/wireless/ath/ath11k/core.c
index 766ae27306f43..e1a6085a065a6 100644
--- a/drivers/net/wireless/ath/ath11k/core.c
+++ b/drivers/net/wireless/ath/ath11k/core.c
@@ -38,6 +38,12 @@ bool ath11k_ftm_mode;
 module_param_named(ftm_mode, ath11k_ftm_mode, bool, 0444);
 MODULE_PARM_DESC(ftm_mode, "Boots up in factory test mode");
 
+/* hw mode values are mapped as per enum wmi_host_hw_mode_config_type */
+unsigned int ath11k_hw_mode = WMI_HOST_HW_MODE_MAX;
+module_param_named(hw_mode, ath11k_hw_mode, uint, 0444);
+MODULE_PARM_DESC(hw_mode,
+		 "Hardware mode (0: single, 1: DBS, 2: SBS passive, 3: SBS, 4: DBS+SBS, 5: DBS or SBS, default: preferred mode the firmware supports)");
+
 static const struct ath11k_hw_params ath11k_hw_params[] = {
 	{
 		.hw_rev = ATH11K_HW_IPQ8074,
diff --git a/drivers/net/wireless/ath/ath11k/core.h b/drivers/net/wireless/ath/ath11k/core.h
index a0d725923ef24..0d81212770019 100644
--- a/drivers/net/wireless/ath/ath11k/core.h
+++ b/drivers/net/wireless/ath/ath11k/core.h
@@ -59,6 +59,7 @@
 #define ATH11K_SMBIOS_BDF_EXT_MAGIC "BDF_"
 
 extern unsigned int ath11k_frame_mode;
+extern unsigned int ath11k_hw_mode;
 extern bool ath11k_ftm_mode;
 
 #define ATH11K_SCAN_TIMEOUT_HZ (20 * HZ)
diff --git a/drivers/net/wireless/ath/ath11k/wmi.c b/drivers/net/wireless/ath/ath11k/wmi.c
index b3c778eb15876..615a8fc0b9937 100644
--- a/drivers/net/wireless/ath/ath11k/wmi.c
+++ b/drivers/net/wireless/ath/ath11k/wmi.c
@@ -4760,9 +4760,9 @@ static int ath11k_wmi_tlv_hw_mode_caps(struct ath11k_base *soc,
 				       u16 len, const void *ptr, void *data)
 {
 	struct wmi_tlv_svc_rdy_ext_parse *svc_rdy_ext = data;
-	struct wmi_hw_mode_capabilities *hw_mode_caps;
+	struct wmi_hw_mode_capabilities *hw_mode_caps, *requested = NULL;
 	enum wmi_host_hw_mode_config_type mode, pref;
-	u32 i;
+	u32 i, modes = 0;
 	int ret;
 
 	svc_rdy_ext->n_hw_mode_caps = 0;
@@ -4783,6 +4783,10 @@ static int ath11k_wmi_tlv_hw_mode_caps(struct ath11k_base *soc,
 		if (mode >= WMI_HOST_HW_MODE_MAX)
 			continue;
 
+		modes |= BIT(mode);
+		if (mode == ath11k_hw_mode)
+			requested = hw_mode_caps;
+
 		pref = soc->wmi_ab.preferred_hw_mode;
 
 		if (ath11k_hw_mode_pri_map[mode] < ath11k_hw_mode_pri_map[pref]) {
@@ -4791,6 +4795,15 @@ static int ath11k_wmi_tlv_hw_mode_caps(struct ath11k_base *soc,
 		}
 	}
 
+	if (requested) {
+		svc_rdy_ext->pref_hw_mode_caps = *requested;
+		soc->wmi_ab.preferred_hw_mode = ath11k_hw_mode;
+	} else if (ath11k_hw_mode != WMI_HOST_HW_MODE_MAX) {
+		ath11k_warn(soc, "hw mode %u not supported (modes 0x%x), using %d\n",
+			    ath11k_hw_mode, modes,
+			    soc->wmi_ab.preferred_hw_mode);
+	}
+
 	ath11k_dbg(soc, ATH11K_DBG_WMI, "preferred_hw_mode:%d\n",
 		   soc->wmi_ab.preferred_hw_mode);
 	if (soc->wmi_ab.preferred_hw_mode == WMI_HOST_HW_MODE_MAX)
-- 
2.53.0