From: Sean Wang Add a dummy register read in mt76_connac_mcu_rate_txpower_band() to act as a PSE barrier. This would release PSE pages and prevents buffer underflow issues when handling MCU commands with larger payloads without the response in mt76_connac_mcu_set_rate_txpower(). This is a prerequisite patch before enabling MT7902 PCIe and SDIO support. Co-developed-by: Xiong Huang Signed-off-by: Xiong Huang Signed-off-by: Sean Wang --- drivers/net/wireless/mediatek/mt76/mt76_connac_mcu.c | 4 ++++ drivers/net/wireless/mediatek/mt76/mt792x_regs.h | 2 ++ 2 files changed, 6 insertions(+) diff --git a/drivers/net/wireless/mediatek/mt76/mt76_connac_mcu.c b/drivers/net/wireless/mediatek/mt76/mt76_connac_mcu.c index d7fbf3454bb8..89bd52ea8bf7 100644 --- a/drivers/net/wireless/mediatek/mt76/mt76_connac_mcu.c +++ b/drivers/net/wireless/mediatek/mt76/mt76_connac_mcu.c @@ -4,6 +4,7 @@ #include #include "mt76_connac2_mac.h" #include "mt76_connac_mcu.h" +#include "mt792x_regs.h" int mt76_connac_mcu_start_firmware(struct mt76_dev *dev, u32 addr, u32 option) { @@ -2246,6 +2247,9 @@ mt76_connac_mcu_rate_txpower_band(struct mt76_phy *phy, false); if (err < 0) goto out; + + /* read a CR to avoid PSE buffer underflow */ + mt76_connac_mcu_reg_rr(dev, MT_PSE_BASE); } out: diff --git a/drivers/net/wireless/mediatek/mt76/mt792x_regs.h b/drivers/net/wireless/mediatek/mt76/mt792x_regs.h index acf627aed609..7ddde9286861 100644 --- a/drivers/net/wireless/mediatek/mt76/mt792x_regs.h +++ b/drivers/net/wireless/mediatek/mt76/mt792x_regs.h @@ -25,6 +25,8 @@ #define MT_PLE_AC_QEMPTY(_n) MT_PLE(0x500 + 0x40 * (_n)) #define MT_PLE_AMSDU_PACK_MSDU_CNT(n) MT_PLE(0x10e0 + ((n) << 2)) +#define MT_PSE_BASE 0x820c8000 + /* TMAC: band 0(0x21000), band 1(0xa1000) */ #define MT_WF_TMAC_BASE(_band) ((_band) ? 0x820f4000 : 0x820e4000) #define MT_WF_TMAC(_band, ofs) (MT_WF_TMAC_BASE(_band) + (ofs)) -- 2.43.0