[PATCH AUTOSEL 6.15 065/118] wifi: iwlwifi: mvm: fix beacon CCK flag

[Sasha Levin <sashal@kernel.org>]

From: Johannes Berg <johannes.berg@intel.com>

[ Upstream commit 8d7f08922a8cb621aa5d00bdce6a7afe57af1665 ]

The beacon CCK flag should be set for any CCK rate, not
just for 1 Mbps. Fix that.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Reviewed-by: Ilan Peer <ilan.peer@intel.com>
Link: https://patch.msgid.link/20250505215513.fe18b7d92d7d.I7bb40a92cea102677b695beb1e2a62a5ea72678b@changeid
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

**YES** This commit should be backported to stable kernel trees based on
my analysis of both the commit message and code changes: ## Analysis of
the Bug Fix **The Bug**: The original code incorrectly sets the beacon
CCK flag: ```c if (rate_idx <= IWL_FIRST_CCK_RATE) // WRONG: Only for 1
Mbps rate ``` **The Fix**: Changes the condition to properly include all
CCK rates: ```c if (rate_idx <= IWL_LAST_CCK_RATE) // CORRECT: For all
CCK rates (1, 2, 5.5, 11 Mbps) ``` ## Why This Should Be Backported ###
1. **Fixes Important Functional Bug** This fixes beacon transmission in
Access Point mode for Intel WiFi devices. The beacon CCK flag tells the
firmware which modulation type to use when transmitting beacons. Setting
it incorrectly could cause: - Beacon transmission failures - Radio
configuration errors - Interoperability issues with client devices -
Power management problems ### 2. **Small, Contained Change** The fix is
minimal and surgical - changing `IWL_FIRST_CCK_RATE` to
`IWL_LAST_CCK_RATE` in a single line. This type of targeted fix has
minimal risk of introducing regressions. ### 3. **Affects Critical
Kernel Subsystem** Wireless networking is a critical subsystem, and
beacon transmission is fundamental to WiFi Access Point operation.
Incorrect beacon formatting could prevent devices from connecting or
maintaining stable connections. ### 4. **Follows Stable Tree Criteria**
- **Important bugfix**: ✅ Fixes beacon transmission logic - **Minimal
risk**: ✅ One-line change with clear purpose - **No new features**: ✅
Pure bug fix - **No architectural changes**: ✅ Simple condition fix -
**Confined to subsystem**: ✅ Only affects iwlwifi driver ### 5.
**Matches Successful Backport Patterns** Looking at the similar commits
provided: - **Similar Commit #2** (YES): Fixed netif checksum flags -
also a small wireless driver fix - **Similar Commit #4** (YES): Fixed
beacon protection flags - nearly identical type of beacon-related fix -
**Similar Commit #5** (YES): Fixed MAC filter flags - another small flag
correction This commit has the same characteristics as those marked for
backporting: small driver fixes that correct important functionality
without architectural changes. ### 6. **Affects User-Visible
Functionality** Users running Intel WiFi devices as Access Points could
experience connection issues due to malformed beacons. This is exactly
the type of bug that stable trees should address. The fix is
straightforward, low-risk, and addresses a functional issue that could
impact real-world WiFi operations, making it an excellent candidate for
stable backporting.

 drivers/net/wireless/intel/iwlwifi/mvm/mac-ctxt.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/mac-ctxt.c b/drivers/net/wireless/intel/iwlwifi/mvm/mac-ctxt.c
index bec18d197f310..83f1ed94ccab9 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/mac-ctxt.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/mac-ctxt.c
@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
 /*
- * Copyright (C) 2012-2014, 2018-2024 Intel Corporation
+ * Copyright (C) 2012-2014, 2018-2025 Intel Corporation
  * Copyright (C) 2013-2014 Intel Mobile Communications GmbH
  * Copyright (C) 2015-2017 Intel Deutschland GmbH
  */
@@ -941,7 +941,7 @@ u16 iwl_mvm_mac_ctxt_get_beacon_flags(const struct iwl_fw *fw, u8 rate_idx)
 	u16 flags = iwl_mvm_mac80211_idx_to_hwrate(fw, rate_idx);
 	bool is_new_rate = iwl_fw_lookup_cmd_ver(fw, BEACON_TEMPLATE_CMD, 0) > 10;
 
-	if (rate_idx <= IWL_FIRST_CCK_RATE)
+	if (rate_idx <= IWL_LAST_CCK_RATE)
 		flags |= is_new_rate ? IWL_MAC_BEACON_CCK
 			  : IWL_MAC_BEACON_CCK_V1;
 
-- 
2.39.5