Re: [PATCH rtw-next v2 10/12] wifi: rtw89: warn unexpected polling value of XTAL SI

[Bitterblue Smith <rtl8821cerfe2@gmail.com>]

On 18/12/2025 08:31, Ping-Ke Shih wrote:
> XTAL SI is an indirect serial interface to access registers in another
> hardware domain. When BT driver initializes UART interface, firmware might
> rarely control XTAL SI at the same time causing access racing.
> 
> Current is to adjust initialization flow to avoid the racing. To make
> the racing visible if it still presents, add a message to address this.
> 
> USB adapters might be unplugged suddenly, causing flooding messages. Check
> RTW89_FLAG_UNPLUGGED flag to avoid them.
> 
> Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
> ---
> v2: handle USB being unplugged case to avoid warnings.
> ---
>  drivers/net/wireless/realtek/rtw89/mac.c    | 31 +++++++++++++++++++--
>  drivers/net/wireless/realtek/rtw89/mac_be.c | 13 ++++++++-
>  2 files changed, 40 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/net/wireless/realtek/rtw89/mac.c b/drivers/net/wireless/realtek/rtw89/mac.c
> index e5f2fa3b2b37..8987077bf756 100644
> --- a/drivers/net/wireless/realtek/rtw89/mac.c
> +++ b/drivers/net/wireless/realtek/rtw89/mac.c
> @@ -1483,6 +1483,15 @@ static void rtw89_mac_power_switch_boot_mode(struct rtw89_dev *rtwdev)
>  	rtw89_write32_clr(rtwdev, R_AX_RSV_CTRL, B_AX_R_DIS_PRST);
>  }
>  
> +static int rtw89_mac_pwr_off_func_for_unplugged(struct rtw89_dev *rtwdev)
> +{
> +	/*
> +	 * Avoid accessing IO for unplugged power-off to prevent warnings,
> +	 * especially XTAL SI.
> +	 */
> +	return 0;
> +}
> +
>  static int rtw89_mac_power_switch(struct rtw89_dev *rtwdev, bool on)
>  {
>  	const struct rtw89_mac_gen_def *mac = rtwdev->chip->mac_def;
> @@ -1497,8 +1506,13 @@ static int rtw89_mac_power_switch(struct rtw89_dev *rtwdev, bool on)
>  		cfg_seq = chip->pwr_on_seq;
>  		cfg_func = chip->ops->pwr_on_func;
>  	} else {
> -		cfg_seq = chip->pwr_off_seq;
> -		cfg_func = chip->ops->pwr_off_func;
> +		if (test_bit(RTW89_FLAG_UNPLUGGED, rtwdev->flags)) {
> +			cfg_seq = NULL;

I just realised, this NULL will be dereferenced in rtw89_mac_pwr_seq().

> +			cfg_func = rtw89_mac_pwr_off_func_for_unplugged;
> +		} else {
> +			cfg_seq = chip->pwr_off_seq;
> +			cfg_func = chip->ops->pwr_off_func;
> +		}
>  	}
>  
>  	if (test_bit(RTW89_FLAG_FW_RDY, rtwdev->flags))
> @@ -7033,6 +7047,12 @@ int rtw89_mac_write_xtal_si_ax(struct rtw89_dev *rtwdev, u8 offset, u8 val, u8 m
>  		return ret;
>  	}
>  
> +	if (!test_bit(RTW89_FLAG_UNPLUGGED, rtwdev->flags) &&
> +	    (u32_get_bits(val32, B_AX_WL_XTAL_SI_ADDR_MASK) != offset ||
> +	     u32_get_bits(val32, B_AX_WL_XTAL_SI_DATA_MASK) != val))
> +		rtw89_warn(rtwdev, "xtal si write: offset=%x val=%x poll=%x\n",
> +			   offset, val, val32);
> +
>  	return 0;
>  }
>  
> @@ -7056,7 +7076,12 @@ int rtw89_mac_read_xtal_si_ax(struct rtw89_dev *rtwdev, u8 offset, u8 *val)
>  		return ret;
>  	}
>  
> -	*val = rtw89_read8(rtwdev, R_AX_WLAN_XTAL_SI_CTRL + 1);
> +	if (!test_bit(RTW89_FLAG_UNPLUGGED, rtwdev->flags) &&
> +	    u32_get_bits(val32, B_AX_WL_XTAL_SI_ADDR_MASK) != offset)
> +		rtw89_warn(rtwdev, "xtal si read: offset=%x poll=%x\n",
> +			   offset, val32);
> +
> +	*val = u32_get_bits(val32, B_AX_WL_XTAL_SI_DATA_MASK);
>  
>  	return 0;
>  }
> diff --git a/drivers/net/wireless/realtek/rtw89/mac_be.c b/drivers/net/wireless/realtek/rtw89/mac_be.c
> index 2bc329c13443..c0204e68c172 100644
> --- a/drivers/net/wireless/realtek/rtw89/mac_be.c
> +++ b/drivers/net/wireless/realtek/rtw89/mac_be.c
> @@ -396,6 +396,12 @@ int rtw89_mac_write_xtal_si_be(struct rtw89_dev *rtwdev, u8 offset, u8 val, u8 m
>  		return ret;
>  	}
>  
> +	if (!test_bit(RTW89_FLAG_UNPLUGGED, rtwdev->flags) &&
> +	    (u32_get_bits(val32, B_BE_WL_XTAL_SI_ADDR_MASK) != offset ||
> +	     u32_get_bits(val32, B_BE_WL_XTAL_SI_DATA_MASK) != val))
> +		rtw89_warn(rtwdev, "xtal si write: offset=%x val=%x poll=%x\n",
> +			   offset, val, val32);
> +
>  	return 0;
>  }
>  
> @@ -420,7 +426,12 @@ int rtw89_mac_read_xtal_si_be(struct rtw89_dev *rtwdev, u8 offset, u8 *val)
>  		return ret;
>  	}
>  
> -	*val = rtw89_read8(rtwdev, R_BE_WLAN_XTAL_SI_CTRL + 1);
> +	if (!test_bit(RTW89_FLAG_UNPLUGGED, rtwdev->flags) &&
> +	    u32_get_bits(val32, B_BE_WL_XTAL_SI_ADDR_MASK) != offset)
> +		rtw89_warn(rtwdev, "xtal si read: offset=%x poll=%x\n",
> +			   offset, val32);
> +
> +	*val = u32_get_bits(val32, B_BE_WL_XTAL_SI_DATA_MASK);
>  
>  	return 0;
>  }