From 06354665f92fa8be36124a8ba7113cdfa40d9df5 Mon Sep 17 00:00:00 2001
From: Wen Gong <wgong@codeaurora.org>
Date: Fri, 6 Sep 2019 10:48:57 +0800
Subject: [PATCH] mac80211: allow drivers to set max MTU
Git-commit: 06354665f92fa8be36124a8ba7113cdfa40d9df5
Patch-mainline: v5.4-rc1
References: jsc#SLE-13430

Make it possibly for drivers to adjust the default max_mtu
by storing it in the hardware struct and using that value
for all interfaces.

Signed-off-by: Wen Gong <wgong@codeaurora.org>
Link: https://lore.kernel.org/r/1567738137-31748-1-git-send-email-wgong@codeaurora.org
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 include/net/mac80211.h | 3 +++
 net/mac80211/iface.c   | 2 +-
 net/mac80211/main.c    | 1 +
 3 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 6781d4637557..523c6a09e1c8 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -2463,6 +2463,8 @@ enum ieee80211_hw_flags {
  *
  * @weight_multiplier: Driver specific airtime weight multiplier used while
  *	refilling deficit of each TXQ.
+ *
+ * @max_mtu: the max mtu could be set.
  */
 struct ieee80211_hw {
 	struct ieee80211_conf conf;
@@ -2500,6 +2502,7 @@ struct ieee80211_hw {
 	u8 max_nan_de_entries;
 	u8 tx_sk_pacing_shift;
 	u8 weight_multiplier;
+	u32 max_mtu;
 };
 
 static inline bool _ieee80211_hw_check(struct ieee80211_hw *hw,
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index 8dc6580e1787..af8b09214786 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -1876,7 +1876,7 @@ int ieee80211_if_add(struct ieee80211_local *local, const char *name,
 
 		/* MTU range: 256 - 2304 */
 		ndev->min_mtu = 256;
-		ndev->max_mtu = IEEE80211_MAX_DATA_LEN;
+		ndev->max_mtu = local->hw.max_mtu;
 
 		ret = register_netdevice(ndev);
 		if (ret) {
diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index 29b9d57df1a3..aba094b4ccfc 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -639,6 +639,7 @@ struct ieee80211_hw *ieee80211_alloc_hw_nm(size_t priv_data_len,
 					 IEEE80211_RADIOTAP_VHT_KNOWN_BANDWIDTH;
 	local->hw.uapsd_queues = IEEE80211_DEFAULT_UAPSD_QUEUES;
 	local->hw.uapsd_max_sp_len = IEEE80211_DEFAULT_MAX_SP_LEN;
+	local->hw.max_mtu = IEEE80211_MAX_DATA_LEN;
 	local->user_power_level = IEEE80211_UNSET_POWER_LEVEL;
 	wiphy->ht_capa_mod_mask = &mac80211_ht_capa_mod_mask;
 	wiphy->vht_capa_mod_mask = &mac80211_vht_capa_mod_mask;
-- 
2.16.4