mac80211: backport ath9k memset fixes from upstream

Backport two upstream commits that replace memset() on coherent DMA
descriptor rings with explicit WRITE_ONCE() status word stores.

On 32-bit PowerPC platforms like apm821xx, coherent DMA memory may be
mapped uncached. The optimized memset() path can use dcbz there, which
triggers alignment warnings and spams the kernel log.

Signed-off-by: Rosen Penev <rosenp@gmail.com>
Link: https://github.com/openwrt/openwrt/pull/23776
Signed-off-by: Jonas Jelonek <jelonek.jonas@gmail.com>

diff --git a/package/kernel/mac80211/patches/ath9k/600-wifi-ath9k-Clear-DMA-descriptors-without-memset.patch b/package/kernel/mac80211/patches/ath9k/600-wifi-ath9k-Clear-DMA-descriptors-without-memset.patch
new file mode 100644 (file)
index 0000000..9c64ae2
--- /dev/null
+++ b/package/kernel/mac80211/patches/ath9k/600-wifi-ath9k-Clear-DMA-descriptors-without-memset.patch
@@ -0,0 +1,108 @@
+From 3e14d832e30b10478d2b0945ff2651f6784385a7 Mon Sep 17 00:00:00 2001
+From: Rosen Penev <rosenp@gmail.com>
+Date: Sat, 16 May 2026 16:43:10 -0700
+Subject: [PATCH] wifi: ath9k: Clear DMA descriptors without memset
+
+Clear ath9k DMA descriptors with explicit status word stores instead of
+memset(). The descriptor rings are coherent DMA memory, which may be
+mapped uncached on 32-bit powerpc. The optimized memset() path can use
+dcbz there and trigger an alignment warning.
+
+Use WRITE_ONCE() for the descriptor status words so the compiler keeps
+the clears as ordinary stores instead of folding them back into bulk
+memset(). This covers AR9003 TX status descriptors as well as the RX
+status area cleared when setting up RX descriptors.
+
+Assisted-by: Codex:GPT-5.5
+Signed-off-by: Rosen Penev <rosenp@gmail.com>
+---
+ drivers/net/wireless/ath/ath9k/ar9002_mac.c | 15 +++++++++++++-
+ drivers/net/wireless/ath/ath9k/ar9003_mac.c | 23 +++++++++++++++++----
+ 2 files changed, 33 insertions(+), 5 deletions(-)
+
+--- a/drivers/net/wireless/ath/ath9k/ar9002_mac.c
++++ b/drivers/net/wireless/ath/ath9k/ar9002_mac.c
+@@ -403,6 +403,19 @@ static int ar9002_hw_get_duration(struct
+       }
+ }
+ 
++static void ath9k_hw_clear_rxdesc_status(struct ar5416_desc *ads)
++{
++      WRITE_ONCE(ads->u.rx.status0, 0);
++      WRITE_ONCE(ads->u.rx.status1, 0);
++      WRITE_ONCE(ads->u.rx.status2, 0);
++      WRITE_ONCE(ads->u.rx.status3, 0);
++      WRITE_ONCE(ads->u.rx.status4, 0);
++      WRITE_ONCE(ads->u.rx.status5, 0);
++      WRITE_ONCE(ads->u.rx.status6, 0);
++      WRITE_ONCE(ads->u.rx.status7, 0);
++      WRITE_ONCE(ads->u.rx.status8, 0);
++}
++
+ void ath9k_hw_setuprxdesc(struct ath_hw *ah, struct ath_desc *ds,
+                         u32 size, u32 flags)
+ {
+@@ -412,7 +425,7 @@ void ath9k_hw_setuprxdesc(struct ath_hw
+       if (flags & ATH9K_RXDESC_INTREQ)
+               ads->ds_ctl1 |= AR_RxIntrReq;
+ 
+-      memset(&ads->u.rx, 0, sizeof(ads->u.rx));
++      ath9k_hw_clear_rxdesc_status(ads);
+ }
+ EXPORT_SYMBOL(ath9k_hw_setuprxdesc);
+ 
+--- a/drivers/net/wireless/ath/ath9k/ar9003_mac.c
++++ b/drivers/net/wireless/ath/ath9k/ar9003_mac.c
+@@ -352,6 +352,19 @@ static bool ar9003_hw_get_isr(struct ath
+       return true;
+ }
+ 
++static void ath9k_hw_clear_txstatus(struct ar9003_txs *ads)
++{
++      WRITE_ONCE(ads->ds_info, 0);
++      WRITE_ONCE(ads->status1, 0);
++      WRITE_ONCE(ads->status2, 0);
++      WRITE_ONCE(ads->status3, 0);
++      WRITE_ONCE(ads->status4, 0);
++      WRITE_ONCE(ads->status5, 0);
++      WRITE_ONCE(ads->status6, 0);
++      WRITE_ONCE(ads->status7, 0);
++      WRITE_ONCE(ads->status8, 0);
++}
++
+ static int ar9003_hw_proc_txdesc(struct ath_hw *ah, void *ds,
+                                struct ath_tx_status *ts)
+ {
+@@ -370,7 +383,7 @@ static int ar9003_hw_proc_txdesc(struct
+           (MS(ads->ds_info, AR_TxRxDesc) != 1)) {
+               ath_dbg(ath9k_hw_common(ah), XMIT,
+                       "Tx Descriptor error %x\n", ads->ds_info);
+-              memset(ads, 0, sizeof(*ads));
++              ath9k_hw_clear_txstatus(ads);
+               return -EIO;
+       }
+ 
+@@ -427,7 +440,7 @@ static int ar9003_hw_proc_txdesc(struct
+       ts->ts_rssi_ext1 = MS(status, AR_TxRSSIAnt11);
+       ts->ts_rssi_ext2 = MS(status, AR_TxRSSIAnt12);
+ 
+-      memset(ads, 0, sizeof(*ads));
++      ath9k_hw_clear_txstatus(ads);
+ 
+       return 0;
+ }
+@@ -591,10 +604,12 @@ EXPORT_SYMBOL(ath9k_hw_process_rxdesc_ed
+ 
+ void ath9k_hw_reset_txstatus_ring(struct ath_hw *ah)
+ {
++      int i;
++
+       ah->ts_tail = 0;
+ 
+-      memset((void *) ah->ts_ring, 0,
+-              ah->ts_size * sizeof(struct ar9003_txs));
++      for (i = 0; i < ah->ts_size; i++)
++              ath9k_hw_clear_txstatus(&ah->ts_ring[i]);
+ 
+       ath_dbg(ath9k_hw_common(ah), XMIT,
+               "TS Start 0x%x End 0x%x Virt %p, Size %d\n",

diff --git a/package/kernel/mac80211/patches/ath9k/601-wifi-ath9k-remove-TX99-power-array-zero-init.patch b/package/kernel/mac80211/patches/ath9k/601-wifi-ath9k-remove-TX99-power-array-zero-init.patch
new file mode 100644 (file)
index 0000000..84c7e67
--- /dev/null
+++ b/package/kernel/mac80211/patches/ath9k/601-wifi-ath9k-remove-TX99-power-array-zero-init.patch
@@ -0,0 +1,34 @@
+From 0da0cfb0840f7fe7df34bde4f787d3435e3db674 Mon Sep 17 00:00:00 2001
+From: Rosen Penev <rosenp@gmail.com>
+Date: Sat, 16 May 2026 20:28:16 -0700
+Subject: [PATCH] wifi: ath9k: remove TX99 power array zero init
+
+This array is fully initialized in the loop itself. No need to zero
+initialize and then overwrite.
+
+Remove static from the array. This was a holdover from when the array
+was a static global variable. It no longer confers any benefit.
+
+Also add a min() call to avoid the manual if/ternary operation.
+
+Assisted-by: Codex:GPT-5.5
+Signed-off-by: Rosen Penev <rosenp@gmail.com>
+---
+ drivers/net/wireless/ath/ath9k/ar9003_phy.c | 4 ++--
+ 1 file changed, 2 insertions(+), 2 deletions(-)
+
+--- a/drivers/net/wireless/ath/ath9k/ar9003_phy.c
++++ b/drivers/net/wireless/ath/ath9k/ar9003_phy.c
+@@ -1737,10 +1737,10 @@ static void ar9003_hw_tx99_stop(struct a
+ 
+ static void ar9003_hw_tx99_set_txpower(struct ath_hw *ah, u8 txpower)
+ {
+-      static u8 p_pwr_array[ar9300RateSize] = { 0 };
++      u8 p_pwr_array[ar9300RateSize];
+       unsigned int i;
+ 
+-      txpower = txpower <= MAX_RATE_POWER ? txpower : MAX_RATE_POWER;
++      txpower = min(txpower, MAX_RATE_POWER);
+       for (i = 0; i < ar9300RateSize; i++)
+               p_pwr_array[i] = txpower;
+