[PATCH wireless 5/5] wifi: b43: Support advertising lack of QoS capability

[Rahul Rameshbabu]

Add b43_qos_not_supported functionality for disabling QoS. Currently, the
function checks an array to see if the chip id matches a value in the
array. If so, disable QoS.

bcm4331 appears to lack QoS support. When queues that are not of the
default "best effort" priority are selected, traffic appears to not
transmit out of the hardware while no errors are returned. This behavior is
present among all the other priority queues: video, voice, and background.
While this can be worked around by setting a kernel parameter, the default
behavior is problematic for most users and may be difficult to debug. This
patch offers a working out-of-box experience for bcm4331 users.

Log of the issue (using ssh low-priority traffic as an example):
    ssh -T -vvvv git@xxxxxxxxxx
    OpenSSH_9.6p1, OpenSSL 3.0.12 24 Oct 2023
    debug1: Reading configuration data /etc/ssh/ssh_config
    debug2: checking match for 'host * exec "/nix/store/q1c2flcykgr4wwg5a6h450hxbk4ch589-bash-5.2-p15/bin/bash -c '/nix/store/c015armnkhr6v18za0rypm7sh1i8js8w-gnupg-2.4.1/bin/gpg-connect-agent --quiet updatestartuptty /bye >/dev/null 2>&1'"' host github.com originally github.com
    debug3: /etc/ssh/ssh_config line 5: matched 'host "github.com"'
    debug1: Executing command: '/nix/store/q1c2flcykgr4wwg5a6h450hxbk4ch589-bash-5.2-p15/bin/bash -c '/nix/store/c015armnkhr6v18za0rypm7sh1i8js8w-gnupg-2.4.1/bin/gpg-connect-agent --quiet updatestartuptty /bye >/dev/null 2>&1''
    debug3: command returned status 0
    debug3: /etc/ssh/ssh_config line 5: matched 'exec "/nix/store/q1c2flcykgr4wwg5a6h450hxbk4ch589-bash-5.2-p15/bin/bash -c '/nix/store/c015armnkhr6v18za0r"'
    debug2: match found
    debug1: /etc/ssh/ssh_config line 9: Applying options for *
    debug3: expanded UserKnownHostsFile '~/.ssh/known_hosts' -> '/home/binary-eater/.ssh/known_hosts'
    debug3: expanded UserKnownHostsFile '~/.ssh/known_hosts2' -> '/home/binary-eater/.ssh/known_hosts2'
    debug2: resolving "github.com" port 22
    debug3: resolve_host: lookup github.com:22
    debug3: channel_clear_timeouts: clearing
    debug3: ssh_connect_direct: entering
    debug1: Connecting to github.com [192.30.255.113] port 22.
    debug3: set_sock_tos: set socket 3 IP_TOS 0x48

Fixes: e6f5b934fba8 ("b43: Add QOS support")
Signed-off-by: Rahul Rameshbabu <sergeantsagara@xxxxxxxxxxxxxx>
---
 drivers/net/wireless/broadcom/b43/main.c | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/drivers/net/wireless/broadcom/b43/main.c b/drivers/net/wireless/broadcom/b43/main.c
index b6ac1526c0e8..39906bebef7b 100644
--- a/drivers/net/wireless/broadcom/b43/main.c
+++ b/drivers/net/wireless/broadcom/b43/main.c
@@ -359,6 +359,22 @@ static struct ieee80211_supported_band b43_band_2ghz_limited = {
 	.n_bitrates	= b43_g_ratetable_size,
 };
 
+static const u16 b43_no_qos_chip_ids[] = {
+	BCMA_CHIP_ID_BCM4331,
+	0,
+};
+
+static bool b43_qos_not_supported(struct b43_wldev *dev)
+{
+	int idx;
+
+	for (idx = 0; b43_no_qos_chip_ids[idx]; idx++)
+		if (dev->dev->chip_id == b43_no_qos_chip_ids[idx])
+			return true;
+
+	return false;
+}
+
 static void b43_wireless_core_exit(struct b43_wldev *dev);
 static int b43_wireless_core_init(struct b43_wldev *dev);
 static struct b43_wldev * b43_wireless_core_stop(struct b43_wldev *dev);
@@ -2587,7 +2603,7 @@ static void b43_request_firmware(struct work_struct *work)
 
 start_ieee80211:
 	wl->hw->queues = B43_QOS_QUEUE_NUM;
-	if (!modparam_qos || dev->fw.opensource)
+	if (!modparam_qos || dev->fw.opensource || b43_qos_not_supported(wl->current_dev))
 		wl->hw->queues = 1;
 
 	err = ieee80211_register_hw(wl->hw);
-- 
2.42.0