6.6-stable review patch. If anyone has any objections, please let me know.
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From: Ping-Ke Shih pkshih@realtek.com
commit c6330b129786e267b14129335a08fa7c331c308d upstream.
The DMA channel of firmware command doesn't use TX WD (WiFi descriptor), so don't need to consider number of TX WD as factor of TX resource. Otherwise, during pause state (a transient state to switch to/from low power mode) firmware commands could be dropped and driver throws warnings suddenly:
rtw89_8852ce 0000:04:00.0: no tx fwcmd resource rtw89_8852ce 0000:04:00.0: failed to send h2c
The case we met is that driver sends RSSI strength of firmware command at RX path that could be running concurrently with switching low power mode. The missing of this firmware command doesn't affect user experiences, because the RSSI strength will be updated again after a while.
The DMA descriptors of normal packets has three layers like:
+-------+ | TX BD | (*n elements) +-------+ | | +-------+ +-> | TX WD | (*m elements) +-------+ | | +--------+ +-> | SKB | +--------+
And, firmware command queue (TXCH 12) is a special queue that has only two layers:
+-------+ | TX BD | (*n elements) +-------+ | | +------------------+ +-> | firmware command | +------------------+
Fixes: 4a29213cd775 ("wifi: rtw89: pci: correct TX resource checking in low power mode") Cc: stable@vger.kernel.org Signed-off-by: Ping-Ke Shih pkshih@realtek.com Link: https://msgid.link/20240410011316.9906-1-pkshih@realtek.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/wireless/realtek/rtw89/pci.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/net/wireless/realtek/rtw89/pci.c +++ b/drivers/net/wireless/realtek/rtw89/pci.c @@ -958,7 +958,8 @@ u32 __rtw89_pci_check_and_reclaim_tx_res
spin_lock_bh(&rtwpci->trx_lock); cnt = rtw89_pci_get_avail_txbd_num(tx_ring); - cnt = min(cnt, wd_ring->curr_num); + if (txch != RTW89_TXCH_CH12) + cnt = min(cnt, wd_ring->curr_num); spin_unlock_bh(&rtwpci->trx_lock);
return cnt;