This read_poll_timeout_atomic() with a delay of 1 µs and a timeout of
1000000 µs can take ~250 seconds in the worst case because sending a
USB control message takes ~250 µs.
Lower the timeout to 4000 for USB in order to reduce the maximum polling
time to ~1 second.
This problem was observed with RTL8851BU while suspending to RAM with
WOWLAN enabled. The computer sat for 4 minutes with a black screen
before suspending.
Signed-off-by: Bitterblue Smith <rtl8821cerfe2@xxxxxxxxx>
---
v2:
- Lower the timeout for USB instead of increasing the delay.
---
drivers/net/wireless/realtek/rtw89/fw.c | 9 +++++++--
drivers/net/wireless/realtek/rtw89/fw.h | 2 ++
2 files changed, 9 insertions(+), 2 deletions(-)
diff --git a/drivers/net/wireless/realtek/rtw89/fw.c b/drivers/net/wireless/realtek/rtw89/fw.c
index 73a4ec988d16..b774a329e7c7 100644
--- a/drivers/net/wireless/realtek/rtw89/fw.c
+++ b/drivers/net/wireless/realtek/rtw89/fw.c
@@ -6755,13 +6755,18 @@ static int rtw89_fw_read_c2h_reg(struct rtw89_dev *rtwdev,
const struct rtw89_chip_info *chip = rtwdev->chip;
struct rtw89_fw_info *fw_info = &rtwdev->fw;
const u32 *c2h_reg = chip->c2h_regs;
- u32 ret;
+ u32 ret, timeout;
u8 i, val;
info->id = RTW89_FWCMD_C2HREG_FUNC_NULL;
+ if (rtwdev->hci.type == RTW89_HCI_TYPE_USB)
+ timeout = RTW89_C2H_TIMEOUT_USB;
+ else
+ timeout = RTW89_C2H_TIMEOUT;
+
ret = read_poll_timeout_atomic(rtw89_read8, val, val, 1,
- RTW89_C2H_TIMEOUT, false, rtwdev,
+ timeout, false, rtwdev,
chip->c2h_ctrl_reg);
if (ret) {
rtw89_warn(rtwdev, "c2h reg timeout\n");
diff --git a/drivers/net/wireless/realtek/rtw89/fw.h b/drivers/net/wireless/realtek/rtw89/fw.h
index 98be7e72c685..a731c242f389 100644
--- a/drivers/net/wireless/realtek/rtw89/fw.h
+++ b/drivers/net/wireless/realtek/rtw89/fw.h
@@ -115,6 +115,8 @@ struct rtw89_h2creg_sch_tx_en {
#define RTW89_C2HREG_HDR_LEN 2
#define RTW89_H2CREG_HDR_LEN 2
#define RTW89_C2H_TIMEOUT 1000000
+#define RTW89_C2H_TIMEOUT_USB 4000
+
struct rtw89_mac_c2h_info {
u8 id;
u8 content_len;
--
2.50.0
