From 823092a53556ebf8656623d0e857626d30fe1e18 Mon Sep 17 00:00:00 2001 From: Ji-Pin Jou Date: Thu, 24 Nov 2022 14:44:42 +0800 Subject: [PATCH] wifi: rtw88: fix race condition when doing H2C command For SDIO/USB interface, since the tranferring speed is slower than that in PCIE, it may have race condition when the driver sets down H2C command to the FW. In the function rtw_fw_send_h2c_command, before the patch, box_reg is written first, then box_ex_reg is written. FW starts to work and fetch the value of box_ex_reg, when the most significant byte of box_reg(4 bytes) is written. Meanwhile, for SDIO/USB interface, since the transferring speed is slow, the driver is still in writing the new value of box_ex_reg through the bus, and FW may get the wrong value of box_ex_reg at the moment. To prevent the above driver/FW racing situation, box_ex_reg is written first then box_reg. Furthermore, it is written in 4 bytes at a time, instead of written in one byte one by one. It can increase the speed for SDIO/USB interface. Signed-off-by: Ji-Pin Jou Signed-off-by: Ping-Ke Shih Tested-by: Sascha Hauer Signed-off-by: Kalle Valo Link: https://lore.kernel.org/r/20221124064442.28042-1-pkshih@realtek.com --- drivers/net/wireless/realtek/rtw88/fw.c | 8 +++----- drivers/net/wireless/realtek/rtw88/fw.h | 5 +++++ 2 files changed, 8 insertions(+), 5 deletions(-) diff --git a/drivers/net/wireless/realtek/rtw88/fw.c b/drivers/net/wireless/realtek/rtw88/fw.c index 0b5f903c0f36..b290811d75e1 100644 --- a/drivers/net/wireless/realtek/rtw88/fw.c +++ b/drivers/net/wireless/realtek/rtw88/fw.c @@ -311,10 +311,10 @@ EXPORT_SYMBOL(rtw_fw_c2h_cmd_isr); static void rtw_fw_send_h2c_command(struct rtw_dev *rtwdev, u8 *h2c) { + struct rtw_h2c_cmd *h2c_cmd = (struct rtw_h2c_cmd *)h2c; u8 box; u8 box_state; u32 box_reg, box_ex_reg; - int idx; int ret; rtw_dbg(rtwdev, RTW_DBG_FW, @@ -356,10 +356,8 @@ static void rtw_fw_send_h2c_command(struct rtw_dev *rtwdev, goto out; } - for (idx = 0; idx < 4; idx++) - rtw_write8(rtwdev, box_reg + idx, h2c[idx]); - for (idx = 0; idx < 4; idx++) - rtw_write8(rtwdev, box_ex_reg + idx, h2c[idx + 4]); + rtw_write32(rtwdev, box_ex_reg, le32_to_cpu(h2c_cmd->msg_ext)); + rtw_write32(rtwdev, box_reg, le32_to_cpu(h2c_cmd->msg)); if (++rtwdev->h2c.last_box_num >= 4) rtwdev->h2c.last_box_num = 0; diff --git a/drivers/net/wireless/realtek/rtw88/fw.h b/drivers/net/wireless/realtek/rtw88/fw.h index a5a965803a3c..bca610dc99ab 100644 --- a/drivers/net/wireless/realtek/rtw88/fw.h +++ b/drivers/net/wireless/realtek/rtw88/fw.h @@ -81,6 +81,11 @@ struct rtw_c2h_adaptivity { u8 option; } __packed; +struct rtw_h2c_cmd { + __le32 msg; + __le32 msg_ext; +} __packed; + enum rtw_rsvd_packet_type { RSVD_BEACON, RSVD_DUMMY, -- 2.11.0