Or in the case of RTL8188EU, report the RSSI to the rate control code.
The rate control code for RTL8188EU is less likely to switch to a lower
rate when the RSSI is high. The firmware-based rate control in the other
chips probably works the same way.
This affects all the chips, but it was only tested with RTL8188EU,
RTL8188FU, and RTL8192EU.
Signed-off-by: Bitterblue Smith <[email protected]>
---
.../net/wireless/realtek/rtl8xxxu/rtl8xxxu.h | 23 +++++++++++++
.../realtek/rtl8xxxu/rtl8xxxu_8188e.c | 6 ++++
.../realtek/rtl8xxxu/rtl8xxxu_8188f.c | 1 +
.../realtek/rtl8xxxu/rtl8xxxu_8192c.c | 1 +
.../realtek/rtl8xxxu/rtl8xxxu_8192e.c | 1 +
.../realtek/rtl8xxxu/rtl8xxxu_8723a.c | 1 +
.../realtek/rtl8xxxu/rtl8xxxu_8723b.c | 1 +
.../wireless/realtek/rtl8xxxu/rtl8xxxu_core.c | 34 +++++++++++++++++++
8 files changed, 68 insertions(+)
diff --git a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu.h b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu.h
index be9479f969b7..90268479d3ad 100644
--- a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu.h
+++ b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu.h
@@ -1168,6 +1168,26 @@ struct h2c_cmd {
u8 cmd;
u8 data;
} __packed bt_grant;
+ struct {
+ u8 cmd;
+ u8 macid;
+ u8 unknown0;
+ u8 rssi;
+ /*
+ * [0] - is_rx
+ * [1] - stbc_en
+ * [2] - noisy_decision
+ * [6] - bf_en
+ */
+ u8 data;
+ /*
+ * [0:6] - ra_th_offset
+ * [7] - ra_offset_direction
+ */
+ u8 ra_th_offset;
+ u8 unknown1;
+ u8 unknown2;
+ } __packed rssi_report;
};
};
@@ -1585,6 +1605,7 @@ struct rtl8xxxu_fileops {
u32 ramask, u8 rateid, int sgi, int txbw_40mhz);
void (*report_connect) (struct rtl8xxxu_priv *priv,
u8 macid, bool connect);
+ void (*report_rssi) (struct rtl8xxxu_priv *priv, u8 macid, u8 rssi);
void (*fill_txdesc) (struct ieee80211_hw *hw, struct ieee80211_hdr *hdr,
struct ieee80211_tx_info *tx_info,
struct rtl8xxxu_txdesc32 *tx_desc, bool sgi,
@@ -1686,6 +1707,8 @@ void rtl8xxxu_gen1_report_connect(struct rtl8xxxu_priv *priv,
u8 macid, bool connect);
void rtl8xxxu_gen2_report_connect(struct rtl8xxxu_priv *priv,
u8 macid, bool connect);
+void rtl8xxxu_gen1_report_rssi(struct rtl8xxxu_priv *priv, u8 macid, u8 rssi);
+void rtl8xxxu_gen2_report_rssi(struct rtl8xxxu_priv *priv, u8 macid, u8 rssi);
void rtl8xxxu_gen1_init_aggregation(struct rtl8xxxu_priv *priv);
void rtl8xxxu_gen1_enable_rf(struct rtl8xxxu_priv *priv);
void rtl8xxxu_gen1_disable_rf(struct rtl8xxxu_priv *priv);
diff --git a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_8188e.c b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_8188e.c
index 37658a090aee..08f3b93ad8d0 100644
--- a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_8188e.c
+++ b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_8188e.c
@@ -1784,6 +1784,11 @@ rtl8188e_update_rate_mask(struct rtl8xxxu_priv *priv,
rtl8188e_arfb_refresh(ra);
}
+static void rtl8188e_ra_set_rssi(struct rtl8xxxu_priv *priv, u8 macid, u8 rssi)
+{
+ priv->ra_info.rssi_sta_ra = rssi;
+}
+
void rtl8188e_ra_info_init_all(struct rtl8xxxu_ra_info *ra)
{
ra->decision_rate = DESC_RATE_MCS7;
@@ -1842,6 +1847,7 @@ struct rtl8xxxu_fileops rtl8188eu_fops = {
.set_tx_power = rtl8188f_set_tx_power,
.update_rate_mask = rtl8188e_update_rate_mask,
.report_connect = rtl8xxxu_gen2_report_connect,
+ .report_rssi = rtl8188e_ra_set_rssi,
.fill_txdesc = rtl8xxxu_fill_txdesc_v3,
.set_crystal_cap = rtl8188f_set_crystal_cap,
.cck_rssi = rtl8188e_cck_rssi,
diff --git a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_8188f.c b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_8188f.c
index f5a0c7a8a581..af6e2c8a5025 100644
--- a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_8188f.c
+++ b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_8188f.c
@@ -1732,6 +1732,7 @@ struct rtl8xxxu_fileops rtl8188fu_fops = {
.set_tx_power = rtl8188f_set_tx_power,
.update_rate_mask = rtl8xxxu_gen2_update_rate_mask,
.report_connect = rtl8xxxu_gen2_report_connect,
+ .report_rssi = rtl8xxxu_gen2_report_rssi,
.fill_txdesc = rtl8xxxu_fill_txdesc_v2,
.set_crystal_cap = rtl8188f_set_crystal_cap,
.cck_rssi = rtl8188f_cck_rssi,
diff --git a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_8192c.c b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_8192c.c
index 8981a86c833f..e61d65c3579b 100644
--- a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_8192c.c
+++ b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_8192c.c
@@ -609,6 +609,7 @@ struct rtl8xxxu_fileops rtl8192cu_fops = {
.set_tx_power = rtl8xxxu_gen1_set_tx_power,
.update_rate_mask = rtl8xxxu_update_rate_mask,
.report_connect = rtl8xxxu_gen1_report_connect,
+ .report_rssi = rtl8xxxu_gen1_report_rssi,
.fill_txdesc = rtl8xxxu_fill_txdesc_v1,
.cck_rssi = rtl8723a_cck_rssi,
.writeN_block_size = 128,
diff --git a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_8192e.c b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_8192e.c
index ca1688600947..4a1c9bcafe31 100644
--- a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_8192e.c
+++ b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_8192e.c
@@ -1784,6 +1784,7 @@ struct rtl8xxxu_fileops rtl8192eu_fops = {
.set_tx_power = rtl8192e_set_tx_power,
.update_rate_mask = rtl8xxxu_gen2_update_rate_mask,
.report_connect = rtl8xxxu_gen2_report_connect,
+ .report_rssi = rtl8xxxu_gen2_report_rssi,
.fill_txdesc = rtl8xxxu_fill_txdesc_v2,
.set_crystal_cap = rtl8723a_set_crystal_cap,
.cck_rssi = rtl8192e_cck_rssi,
diff --git a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_8723a.c b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_8723a.c
index e881ee33c6e8..5ed523db2d87 100644
--- a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_8723a.c
+++ b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_8723a.c
@@ -478,6 +478,7 @@ struct rtl8xxxu_fileops rtl8723au_fops = {
.set_tx_power = rtl8xxxu_gen1_set_tx_power,
.update_rate_mask = rtl8xxxu_update_rate_mask,
.report_connect = rtl8xxxu_gen1_report_connect,
+ .report_rssi = rtl8xxxu_gen1_report_rssi,
.fill_txdesc = rtl8xxxu_fill_txdesc_v1,
.set_crystal_cap = rtl8723a_set_crystal_cap,
.cck_rssi = rtl8723a_cck_rssi,
diff --git a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_8723b.c b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_8723b.c
index 0ed667d5ed25..21613d60dc22 100644
--- a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_8723b.c
+++ b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_8723b.c
@@ -1727,6 +1727,7 @@ struct rtl8xxxu_fileops rtl8723bu_fops = {
.set_tx_power = rtl8723b_set_tx_power,
.update_rate_mask = rtl8xxxu_gen2_update_rate_mask,
.report_connect = rtl8xxxu_gen2_report_connect,
+ .report_rssi = rtl8xxxu_gen2_report_rssi,
.fill_txdesc = rtl8xxxu_fill_txdesc_v2,
.set_crystal_cap = rtl8723a_set_crystal_cap,
.cck_rssi = rtl8723b_cck_rssi,
diff --git a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
index fd97c040948a..f5fd3c448587 100644
--- a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
+++ b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
@@ -4461,6 +4461,37 @@ void rtl8xxxu_gen2_report_connect(struct rtl8xxxu_priv *priv,
rtl8xxxu_gen2_h2c_cmd(priv, &h2c, sizeof(h2c.media_status_rpt));
}
+void rtl8xxxu_gen1_report_rssi(struct rtl8xxxu_priv *priv, u8 macid, u8 rssi)
+{
+ struct h2c_cmd h2c;
+ const int h2c_size = 3;
+
+ memset(&h2c, 0, sizeof(struct h2c_cmd));
+
+ h2c.rssi_report.cmd = H2C_SET_RSSI;
+ h2c.rssi_report.macid = macid;
+ h2c.rssi_report.rssi = rssi;
+
+ rtl8xxxu_gen1_h2c_cmd(priv, &h2c, h2c_size);
+}
+
+void rtl8xxxu_gen2_report_rssi(struct rtl8xxxu_priv *priv, u8 macid, u8 rssi)
+{
+ struct h2c_cmd h2c;
+ int h2c_size = sizeof(h2c.rssi_report);
+
+ if (priv->rtl_chip == RTL8723B)
+ h2c_size = 4;
+
+ memset(&h2c, 0, sizeof(struct h2c_cmd));
+
+ h2c.rssi_report.cmd = H2C_8723B_RSSI_SETTING;
+ h2c.rssi_report.macid = macid;
+ h2c.rssi_report.rssi = rssi;
+
+ rtl8xxxu_gen2_h2c_cmd(priv, &h2c, h2c_size);
+}
+
void rtl8xxxu_gen1_init_aggregation(struct rtl8xxxu_priv *priv)
{
u8 agg_ctrl, usb_spec, page_thresh, timeout;
@@ -6701,6 +6732,9 @@ static void rtl8xxxu_watchdog_callback(struct work_struct *work)
signal = ieee80211_ave_rssi(vif);
+ priv->fops->report_rssi(priv, 0,
+ rtl8xxxu_signal_to_snr(signal));
+
if (priv->fops->set_crystal_cap)
rtl8xxxu_track_cfo(priv);
--
2.38.0
The Realtek rate control algorithm goes back and forth a lot between
the highest and the lowest rate it's allowed to use. This is due to
a lot of frames being dropped because the retry limits set by
IEEE80211_CONF_CHANGE_RETRY_LIMITS are too low. (Experimentally, they
are 4 for long frames and 7 for short frames.)
The vendor drivers hardcode the value 48 for both retry limits (for
station mode), which makes dropped frames very rare and thus the rate
control is more stable.
Because most Realtek chips handle the rate control in the firmware,
which can't be modified, ignore the limits set by
IEEE80211_CONF_CHANGE_RETRY_LIMITS and use the value 48 (set during
chip initialisation), same as the vendor drivers.
Fixes: 26f1fad29ad9 ("New driver: rtl8xxxu (mac80211)")
Signed-off-by: Bitterblue Smith <[email protected]>
---
drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c | 9 ---------
1 file changed, 9 deletions(-)
diff --git a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
index f5fd3c448587..9bca5e837583 100644
--- a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
+++ b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
@@ -6184,7 +6184,6 @@ static int rtl8xxxu_config(struct ieee80211_hw *hw, u32 changed)
{
struct rtl8xxxu_priv *priv = hw->priv;
struct device *dev = &priv->udev->dev;
- u16 val16;
int ret = 0, channel;
bool ht40;
@@ -6194,14 +6193,6 @@ static int rtl8xxxu_config(struct ieee80211_hw *hw, u32 changed)
__func__, hw->conf.chandef.chan->hw_value,
changed, hw->conf.chandef.width);
- if (changed & IEEE80211_CONF_CHANGE_RETRY_LIMITS) {
- val16 = ((hw->conf.long_frame_max_tx_count <<
- RETRY_LIMIT_LONG_SHIFT) & RETRY_LIMIT_LONG_MASK) |
- ((hw->conf.short_frame_max_tx_count <<
- RETRY_LIMIT_SHORT_SHIFT) & RETRY_LIMIT_SHORT_MASK);
- rtl8xxxu_write16(priv, REG_RETRY_LIMIT, val16);
- }
-
if (changed & IEEE80211_CONF_CHANGE_CHANNEL) {
switch (hw->conf.chandef.width) {
case NL80211_CHAN_WIDTH_20_NOHT:
--
2.38.0
> -----Original Message-----
> From: Bitterblue Smith <[email protected]>
> Sent: Saturday, December 31, 2022 12:52 AM
> To: [email protected]
> Cc: Jes Sorensen <[email protected]>; Ping-Ke Shih <[email protected]>
> Subject: [PATCH 1/2] wifi: rtl8xxxu: Report the RSSI to the firmware
>
> Or in the case of RTL8188EU, report the RSSI to the rate control code.
>
> The rate control code for RTL8188EU is less likely to switch to a lower
> rate when the RSSI is high. The firmware-based rate control in the other
> chips probably works the same way.
>
> This affects all the chips, but it was only tested with RTL8188EU,
> RTL8188FU, and RTL8192EU.
>
> Signed-off-by: Bitterblue Smith <[email protected]>
> ---
> .../net/wireless/realtek/rtl8xxxu/rtl8xxxu.h | 23 +++++++++++++
> .../realtek/rtl8xxxu/rtl8xxxu_8188e.c | 6 ++++
> .../realtek/rtl8xxxu/rtl8xxxu_8188f.c | 1 +
> .../realtek/rtl8xxxu/rtl8xxxu_8192c.c | 1 +
> .../realtek/rtl8xxxu/rtl8xxxu_8192e.c | 1 +
> .../realtek/rtl8xxxu/rtl8xxxu_8723a.c | 1 +
> .../realtek/rtl8xxxu/rtl8xxxu_8723b.c | 1 +
> .../wireless/realtek/rtl8xxxu/rtl8xxxu_core.c | 34 +++++++++++++++++++
> 8 files changed, 68 insertions(+)
>
[...]
> diff --git a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
> b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
> index fd97c040948a..f5fd3c448587 100644
> --- a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
> +++ b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
> @@ -4461,6 +4461,37 @@ void rtl8xxxu_gen2_report_connect(struct rtl8xxxu_priv *priv,
> rtl8xxxu_gen2_h2c_cmd(priv, &h2c, sizeof(h2c.media_status_rpt));
> }
>
> +void rtl8xxxu_gen1_report_rssi(struct rtl8xxxu_priv *priv, u8 macid, u8 rssi)
> +{
> + struct h2c_cmd h2c;
> + const int h2c_size = 3;
Shouldn't it be 4?
struct {
u8 cmd;
u8 macid;
u8 unknown0;
u8 rssi; // you fill this field.
> +
> + memset(&h2c, 0, sizeof(struct h2c_cmd));
> +
> + h2c.rssi_report.cmd = H2C_SET_RSSI;
> + h2c.rssi_report.macid = macid;
> + h2c.rssi_report.rssi = rssi;
> +
> + rtl8xxxu_gen1_h2c_cmd(priv, &h2c, h2c_size);
> +}
> +
[...]
> -----Original Message-----
> From: Bitterblue Smith <[email protected]>
> Sent: Saturday, December 31, 2022 12:54 AM
> To: [email protected]
> Cc: Jes Sorensen <[email protected]>; Ping-Ke Shih <[email protected]>
> Subject: [PATCH 2/2] wifi: rtl8xxxu: Use a longer retry limit of 48
>
> The Realtek rate control algorithm goes back and forth a lot between
> the highest and the lowest rate it's allowed to use. This is due to
> a lot of frames being dropped because the retry limits set by
> IEEE80211_CONF_CHANGE_RETRY_LIMITS are too low. (Experimentally, they
> are 4 for long frames and 7 for short frames.)
>
> The vendor drivers hardcode the value 48 for both retry limits (for
> station mode), which makes dropped frames very rare and thus the rate
> control is more stable.
I have similar feeling with Realtek 802.11ac chips as well, but I didn't
dig further years ago. Maybe, it could have TX EVM problem.
>
> Because most Realtek chips handle the rate control in the firmware,
> which can't be modified, ignore the limits set by
> IEEE80211_CONF_CHANGE_RETRY_LIMITS and use the value 48 (set during
> chip initialisation), same as the vendor drivers.
>
> Fixes: 26f1fad29ad9 ("New driver: rtl8xxxu (mac80211)")
No sure if "Fixes" is suitable to this patch, because original looks well but
bad performance in real.
> Signed-off-by: Bitterblue Smith <[email protected]>
Reviewed-by: Ping-Ke Shih <[email protected]>
> ---
> drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c | 9 ---------
> 1 file changed, 9 deletions(-)
>
> diff --git a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
> b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
> index f5fd3c448587..9bca5e837583 100644
> --- a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
> +++ b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
> @@ -6184,7 +6184,6 @@ static int rtl8xxxu_config(struct ieee80211_hw *hw, u32 changed)
> {
> struct rtl8xxxu_priv *priv = hw->priv;
> struct device *dev = &priv->udev->dev;
> - u16 val16;
> int ret = 0, channel;
> bool ht40;
>
> @@ -6194,14 +6193,6 @@ static int rtl8xxxu_config(struct ieee80211_hw *hw, u32 changed)
> __func__, hw->conf.chandef.chan->hw_value,
> changed, hw->conf.chandef.width);
>
> - if (changed & IEEE80211_CONF_CHANGE_RETRY_LIMITS) {
> - val16 = ((hw->conf.long_frame_max_tx_count <<
> - RETRY_LIMIT_LONG_SHIFT) & RETRY_LIMIT_LONG_MASK) |
> - ((hw->conf.short_frame_max_tx_count <<
> - RETRY_LIMIT_SHORT_SHIFT) & RETRY_LIMIT_SHORT_MASK);
> - rtl8xxxu_write16(priv, REG_RETRY_LIMIT, val16);
> - }
> -
> if (changed & IEEE80211_CONF_CHANGE_CHANNEL) {
> switch (hw->conf.chandef.width) {
> case NL80211_CHAN_WIDTH_20_NOHT:
> --
> 2.38.0
>
> ------Please consider the environment before printing this e-mail.
On 03/01/2023 10:05, Ping-Ke Shih wrote:
>
>
>> -----Original Message-----
>> From: Bitterblue Smith <[email protected]>
>> Sent: Saturday, December 31, 2022 12:52 AM
>> To: [email protected]
>> Cc: Jes Sorensen <[email protected]>; Ping-Ke Shih <[email protected]>
>> Subject: [PATCH 1/2] wifi: rtl8xxxu: Report the RSSI to the firmware
>>
>> Or in the case of RTL8188EU, report the RSSI to the rate control code.
>>
>> The rate control code for RTL8188EU is less likely to switch to a lower
>> rate when the RSSI is high. The firmware-based rate control in the other
>> chips probably works the same way.
>>
>> This affects all the chips, but it was only tested with RTL8188EU,
>> RTL8188FU, and RTL8192EU.
>>
>> Signed-off-by: Bitterblue Smith <[email protected]>
>> ---
>> .../net/wireless/realtek/rtl8xxxu/rtl8xxxu.h | 23 +++++++++++++
>> .../realtek/rtl8xxxu/rtl8xxxu_8188e.c | 6 ++++
>> .../realtek/rtl8xxxu/rtl8xxxu_8188f.c | 1 +
>> .../realtek/rtl8xxxu/rtl8xxxu_8192c.c | 1 +
>> .../realtek/rtl8xxxu/rtl8xxxu_8192e.c | 1 +
>> .../realtek/rtl8xxxu/rtl8xxxu_8723a.c | 1 +
>> .../realtek/rtl8xxxu/rtl8xxxu_8723b.c | 1 +
>> .../wireless/realtek/rtl8xxxu/rtl8xxxu_core.c | 34 +++++++++++++++++++
>> 8 files changed, 68 insertions(+)
>>
>
> [...]
>
>> diff --git a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
>> b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
>> index fd97c040948a..f5fd3c448587 100644
>> --- a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
>> +++ b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
>> @@ -4461,6 +4461,37 @@ void rtl8xxxu_gen2_report_connect(struct rtl8xxxu_priv *priv,
>> rtl8xxxu_gen2_h2c_cmd(priv, &h2c, sizeof(h2c.media_status_rpt));
>> }
>>
>> +void rtl8xxxu_gen1_report_rssi(struct rtl8xxxu_priv *priv, u8 macid, u8 rssi)
>> +{
>> + struct h2c_cmd h2c;
>> + const int h2c_size = 3;
>
> Shouldn't it be 4?
>
> struct {
> u8 cmd;
> u8 macid;
> u8 unknown0;
> u8 rssi; // you fill this field.
>
I probably copied that from the vendor driver, which doesn't count the
cmd field. But it turns out it doesn't matter. 3 and 4 will have the
same effect here. rtl8xxxu_gen1_h2c_cmd() only checks if the size is
greater than 4 or not.
But I suppose 4 is less confusing, so I'll change it.
>> +
>> + memset(&h2c, 0, sizeof(struct h2c_cmd));
>> +
>> + h2c.rssi_report.cmd = H2C_SET_RSSI;
>> + h2c.rssi_report.macid = macid;
>> + h2c.rssi_report.rssi = rssi;
>> +
>> + rtl8xxxu_gen1_h2c_cmd(priv, &h2c, h2c_size);
>> +}
>> +
>
> [...]
>
>
On 03/01/2023 10:13, Ping-Ke Shih wrote:
>
>> -----Original Message-----
>> From: Bitterblue Smith <[email protected]>
>> Sent: Saturday, December 31, 2022 12:54 AM
>> To: [email protected]
>> Cc: Jes Sorensen <[email protected]>; Ping-Ke Shih <[email protected]>
>> Subject: [PATCH 2/2] wifi: rtl8xxxu: Use a longer retry limit of 48
>>
>> The Realtek rate control algorithm goes back and forth a lot between
>> the highest and the lowest rate it's allowed to use. This is due to
>> a lot of frames being dropped because the retry limits set by
>> IEEE80211_CONF_CHANGE_RETRY_LIMITS are too low. (Experimentally, they
>> are 4 for long frames and 7 for short frames.)
>>
>> The vendor drivers hardcode the value 48 for both retry limits (for
>> station mode), which makes dropped frames very rare and thus the rate
>> control is more stable.
>
> I have similar feeling with Realtek 802.11ac chips as well, but I didn't
> dig further years ago. Maybe, it could have TX EVM problem.
>
>>
>> Because most Realtek chips handle the rate control in the firmware,
>> which can't be modified, ignore the limits set by
>> IEEE80211_CONF_CHANGE_RETRY_LIMITS and use the value 48 (set during
>> chip initialisation), same as the vendor drivers.
>>
>> Fixes: 26f1fad29ad9 ("New driver: rtl8xxxu (mac80211)")
>
> No sure if "Fixes" is suitable to this patch, because original looks well but
> bad performance in real.
>
Mostly I care about the Fixes tag because it gets the patch into the
stable kernels, but I can use the Cc tag for that instead.
>> Signed-off-by: Bitterblue Smith <[email protected]>
>
> Reviewed-by: Ping-Ke Shih <[email protected]>
>
>> ---
>> drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c | 9 ---------
>> 1 file changed, 9 deletions(-)
>>
>> diff --git a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
>> b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
>> index f5fd3c448587..9bca5e837583 100644
>> --- a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
>> +++ b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
>> @@ -6184,7 +6184,6 @@ static int rtl8xxxu_config(struct ieee80211_hw *hw, u32 changed)
>> {
>> struct rtl8xxxu_priv *priv = hw->priv;
>> struct device *dev = &priv->udev->dev;
>> - u16 val16;
>> int ret = 0, channel;
>> bool ht40;
>>
>> @@ -6194,14 +6193,6 @@ static int rtl8xxxu_config(struct ieee80211_hw *hw, u32 changed)
>> __func__, hw->conf.chandef.chan->hw_value,
>> changed, hw->conf.chandef.width);
>>
>> - if (changed & IEEE80211_CONF_CHANGE_RETRY_LIMITS) {
>> - val16 = ((hw->conf.long_frame_max_tx_count <<
>> - RETRY_LIMIT_LONG_SHIFT) & RETRY_LIMIT_LONG_MASK) |
>> - ((hw->conf.short_frame_max_tx_count <<
>> - RETRY_LIMIT_SHORT_SHIFT) & RETRY_LIMIT_SHORT_MASK);
>> - rtl8xxxu_write16(priv, REG_RETRY_LIMIT, val16);
>> - }
>> -
>> if (changed & IEEE80211_CONF_CHANGE_CHANNEL) {
>> switch (hw->conf.chandef.width) {
>> case NL80211_CHAN_WIDTH_20_NOHT:
>> --
>> 2.38.0
>>
>> ------Please consider the environment before printing this e-mail.