Hello Ping-Ke Shih,
The patch e3ec7017f6a2: "rtw89: add Realtek 802.11ax driver" from Oct
11, 2021, leads to the following potential issue (just from reading
the code):
drivers/net/wireless/realtek/rtw89/core.h
3878 static inline u32
3879 rtw89_read32_mask(struct rtw89_dev *rtwdev, u32 addr, u32 mask)
3880 {
3881 u32 shift = __ffs(mask);
3882 u32 orig;
3883 u32 ret;
3884
3885 orig = rtw89_read32(rtwdev, addr);
--> 3886 ret = (orig & mask) >> shift;
I think this line should be:
ret = (orig & mask) >> (shift - 1);
A typical mask here is 0xff so __ffs() is 1 because the first bit is
set. This code will do: ret = (orig & 0xff) >> 1; I think it should be
ret = (orig & 0xff) >> 0;
If the mask was 0xff00 I would expect >> 8 instead of >> 9 etc.
3887
3888 return ret;
3889 }
regards,
dan carpenter
