wifi: rtw89: pci: correct TX resource checking in low power mode

Number of TX resource must be minimum of TX_BD and TX_WD. Only considering
TX_BD could drop TX packets pulled from mac80211 if TX_WD is unavailable.

Fixes: 52edbb9f ("rtw89: ps: access TX/RX rings via another registers in low power mode")
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20220824063312.15784-2-pkshih@realtek.com

drivers/net/wireless/realtek/rtw89/pci.c

@@ -926,10 +926,12 @@ u32 __rtw89_pci_check_and_reclaim_tx_resource_noio(struct rtw89_dev *rtwdev,
 {
 	struct rtw89_pci *rtwpci = (struct rtw89_pci *)rtwdev->priv;
 	struct rtw89_pci_tx_ring *tx_ring = &rtwpci->tx_rings[txch];
+	struct rtw89_pci_tx_wd_ring *wd_ring = &tx_ring->wd_ring;
 	u32 cnt;
 
 	spin_lock_bh(&rtwpci->trx_lock);
 	cnt = rtw89_pci_get_avail_txbd_num(tx_ring);
+	cnt = min(cnt, wd_ring->curr_num);
 	spin_unlock_bh(&rtwpci->trx_lock);
 
 	return cnt;