On Sat, Aug 05, 2023 at 05:17:55PM +0800, Shiji Yang wrote:
> In the vendor driver, the current channel power is queried from
> EEPROM_TXPOWER_BG1 and EEPROM_TXPOWER_BG2. And then the mixed value
> will be written into the low half-word of the TX_ALC_CFG_0 register.
> The high half-word of the TX_ALC_CFG_0 is a fixed value 0x2f2f.
>
> We can't get the accurate TX power. Based on my tests and the new
> MediaTek mt76 driver source code, the real TX power is approximately
> equal to channel_power + (max) rate_power. Usually max rate_power is
> the gain of the OFDM 6M rate, which can be readed from the offset
> EEPROM_TXPOWER_BYRATE +1.
>
> Based on these eeprom values, this patch adds basic TX power control
> for the MT7620 and limits its maximum TX power. This can avoid the
> link speed decrease caused by chip overheating. rt2800_config_alc()
> function has also been renamed to rt2800_config_alc_rt6352() because
> it's only used by RT6352(MT7620).
>
> Notice:
> It's still need some work to sync the max channel power to the user
> interface. This part is missing from the rt2x00 driver framework. If
> we set the power exceed the calibration value, it won't take effect.
>
> Signed-off-by: Shiji Yang <yangshiji66@xxxxxxxxxxx>
> ---
> .../net/wireless/ralink/rt2x00/rt2800lib.c | 56 +++++++++++++------
> 1 file changed, 39 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/net/wireless/ralink/rt2x00/rt2800lib.c b/drivers/net/wireless/ralink/rt2x00/rt2800lib.c
> index 1226a883c..ff891353c 100644
> --- a/drivers/net/wireless/ralink/rt2x00/rt2800lib.c
> +++ b/drivers/net/wireless/ralink/rt2x00/rt2800lib.c
> @@ -3865,28 +3865,50 @@ static void rt2800_config_channel_rf7620(struct rt2x00_dev *rt2x00dev,
> }
> }
>
> -static void rt2800_config_alc(struct rt2x00_dev *rt2x00dev,
> - struct ieee80211_channel *chan,
> - int power_level) {
> - u16 eeprom, target_power, max_power;
> +static void rt2800_config_alc_rt6352(struct rt2x00_dev *rt2x00dev,
> + struct ieee80211_channel *chan,
> + int power_level)
> +{
> + u16 eeprom, chan_power, rate_power, target_power;
> + u16 tx_power[2];
> + s8 *power_group[2];
> u32 mac_sys_ctrl;
> - u32 reg;
> + u32 cnt, reg;
> u8 bbp;
>
> - /* hardware unit is 0.5dBm, limited to 23.5dBm */
> - power_level *= 2;
> - if (power_level > 0x2f)
> - power_level = 0x2f;
> + /* get per chain power, 2 chains in total, unit is 0.5dBm */
> + power_level = (power_level - 3) * 2;
> +
> + /*
> + * We can't get the accurate TX power. Based on some tests, the real
> + * TX power is approximately equal to channel_power + (max)rate_power.
> + * Usually max rate_power is the gain of the OFDM 6M rate. The antenna
> + * gain and externel PA gain are not included as we are unable to
> + * obtain these values.
> + */
> + rate_power = rt2800_eeprom_read_from_array(rt2x00dev,
> + EEPROM_TXPOWER_BYRATE, 1);
> + rate_power &= 0x3f;
> + power_level -= rate_power;
> + if (power_level < 1)
> + power_level = 1;
> + if (power_level > chan->max_power * 2)
> + power_level = chan->max_power * 2;
>
> - max_power = chan->max_power * 2;
> - if (max_power > 0x2f)
> - max_power = 0x2f;
> + power_group[0] = rt2800_eeprom_addr(rt2x00dev, EEPROM_TXPOWER_BG1);
> + power_group[1] = rt2800_eeprom_addr(rt2x00dev, EEPROM_TXPOWER_BG2);
> + for (cnt = 0; cnt < 2; cnt++) {
> + chan_power = power_group[cnt][rt2x00dev->rf_channel - 1];
I whould add
if (WARN_ON(rt2x00dev->rf_channel not in proper range))
return;
just to be on safe side. This can be done in separate patch, if you think
it is appropriate.
The change overall looks ok to me.
Acked-by: Stanislaw Gruszka <stf_xl@xxxxx>
