[3.5.y.z extended stable] Patch "rtlwifi: rtl8192ce: Fix too long disable of IRQs" has been added to staging queue
Luis Henriques
luis.henriques at canonical.com
Wed Feb 26 13:24:58 UTC 2014
This is a note to let you know that I have just added a patch titled
rtlwifi: rtl8192ce: Fix too long disable of IRQs
to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree
which can be found at:
http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue
If you, or anyone else, feels it should not be added to this tree, please
reply to this email.
For more information about the 3.5.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable
Thanks.
-Luis
------
>From bb2b4aa83b91d2aa7bafea99e82ce4a18db90240 Mon Sep 17 00:00:00 2001
From: Olivier Langlois <olivier at trillion01.com>
Date: Sat, 1 Feb 2014 01:11:09 -0500
Subject: rtlwifi: rtl8192ce: Fix too long disable of IRQs
commit f78bccd79ba3cd9d9664981b501d57bdb81ab8a4 upstream.
rtl8192ce is disabling for too long the local interrupts during hw initiatialisation when performing scans
The observable symptoms in dmesg can be:
- underruns from ALSA playback
- clock freezes (tstamps do not change for several dmesg entries until irqs are finaly reenabled):
[ 250.817669] rtlwifi:rtl_op_config():<0-0-0> 0x100
[ 250.817685] rtl8192ce:_rtl92ce_phy_set_rf_power_state():<0-1-0> IPS Set eRf nic enable
[ 250.817732] rtl8192ce:_rtl92ce_init_mac():<0-1-0> reg0xec:18051d59:11
[ 250.817796] rtl8192ce:_rtl92ce_init_mac():<0-1-0> reg0xec:18051d59:11
[ 250.817910] rtl8192ce:_rtl92ce_init_mac():<0-1-0> reg0xec:18051d59:11
[ 250.818024] rtl8192ce:_rtl92ce_init_mac():<0-1-0> reg0xec:18051d59:11
[ 250.818139] rtl8192ce:_rtl92ce_init_mac():<0-1-0> reg0xec:18051d59:11
[ 250.818253] rtl8192ce:_rtl92ce_init_mac():<0-1-0> reg0xec:18051d59:11
[ 250.818367] rtl8192ce:_rtl92ce_init_mac():<0-1-0> reg0xec:18051d59:11
[ 250.818472] rtl8192ce:_rtl92ce_init_mac():<0-1-0> reg0xec:18051d59:11
[ 250.818472] rtl8192ce:_rtl92ce_init_mac():<0-1-0> reg0xec:18051d59:11
[ 250.818472] rtl8192ce:_rtl92ce_init_mac():<0-1-0> reg0xec:18051d59:11
[ 250.818472] rtl8192ce:_rtl92ce_init_mac():<0-1-0> reg0xec:18051d59:11
[ 250.818472] rtl8192ce:_rtl92ce_init_mac():<0-1-0> reg0xec:98053f15:10
[ 250.818472] rtl8192ce:rtl92ce_sw_led_on():<0-1-0> LedAddr:4E ledpin=1
[ 250.818472] rtl8192c_common:rtl92c_download_fw():<0-1-0> Firmware Version(49), Signature(0x88c1),Size(32)
[ 250.818472] rtl8192ce:rtl92ce_enable_hw_security_config():<0-1-0> PairwiseEncAlgorithm = 0 GroupEncAlgorithm = 0
[ 250.818472] rtl8192ce:rtl92ce_enable_hw_security_config():<0-1-0> The SECR-value cc
[ 250.818472] rtl8192c_common:rtl92c_dm_check_txpower_tracking_thermal_meter():<0-1-0> Schedule TxPowerTracking direct call!!
[ 250.818472] rtl8192c_common:rtl92c_dm_txpower_tracking_callback_thermalmeter():<0-1-0> rtl92c_dm_txpower_tracking_callback_thermalmeter
[ 250.818472] rtl8192c_common:rtl92c_dm_txpower_tracking_callback_thermalmeter():<0-1-0> Readback Thermal Meter = 0xe pre thermal meter 0xf eeprom_thermalmeter 0xf
[ 250.818472] rtl8192c_common:rtl92c_dm_txpower_tracking_callback_thermalmeter():<0-1-0> Initial pathA ele_d reg0xc80 = 0x40000000, ofdm_index=0xc
[ 250.818472] rtl8192c_common:rtl92c_dm_txpower_tracking_callback_thermalmeter():<0-1-0> Initial reg0xa24 = 0x90e1317, cck_index=0xc, ch14 0
[ 250.818472] rtl8192c_common:rtl92c_dm_txpower_tracking_callback_thermalmeter():<0-1-0> Readback Thermal Meter = 0xe pre thermal meter 0xf eeprom_thermalmeter 0xf delta 0x1 delta_lck 0x0 delta_iqk 0x0
[ 250.818472] rtl8192c_common:rtl92c_dm_txpower_tracking_callback_thermalmeter():<0-1-0> <===
[ 250.818472] rtl8192c_common:rtl92c_dm_initialize_txpower_tracking_thermalmeter():<0-1-0> pMgntInfo->txpower_tracking = 1
[ 250.818472] rtl8192ce:rtl92ce_led_control():<0-1-0> ledaction 3
[ 250.818472] rtl8192ce:rtl92ce_sw_led_on():<0-1-0> LedAddr:4E ledpin=1
[ 250.818472] rtlwifi:rtl_ips_nic_on():<0-1-0> before spin_unlock_irqrestore
[ 251.154656] PCM: Lost interrupts? [Q]-0 (stream=0, delta=15903, new_hw_ptr=293408, old_hw_ptr=277505)
The exact code flow that causes that is:
1. wpa_supplicant send a start_scan request to the nl80211 driver
2. mac80211 module call rtl_op_config with IEEE80211_CONF_CHANGE_IDLE
3. rtl_ips_nic_on is called which disable local irqs
4. rtl92c_phy_set_rf_power_state() is called
5. rtl_ps_enable_nic() is called and hw_init()is executed and then the interrupts on the device are enabled
A good solution could be to refactor the code to avoid calling rtl92ce_hw_init() with the irqs disabled
but a quick and dirty solution that has proven to work is
to reenable the irqs during the function rtl92ce_hw_init().
I think that it is safe doing so since the device interrupt will only be enabled after the init function succeed.
Signed-off-by: Olivier Langlois <olivier at trillion01.com>
Acked-by: Larry Finger <Larry.Finger at lwfinger.net>
Signed-off-by: John W. Linville <linville at tuxdriver.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
drivers/net/wireless/rtlwifi/rtl8192ce/hw.c | 18 ++++++++++++++++--
1 file changed, 16 insertions(+), 2 deletions(-)
diff --git a/drivers/net/wireless/rtlwifi/rtl8192ce/hw.c b/drivers/net/wireless/rtlwifi/rtl8192ce/hw.c
index 509f661..18ddf57 100644
--- a/drivers/net/wireless/rtlwifi/rtl8192ce/hw.c
+++ b/drivers/net/wireless/rtlwifi/rtl8192ce/hw.c
@@ -902,14 +902,26 @@ int rtl92ce_hw_init(struct ieee80211_hw *hw)
bool is92c;
int err;
u8 tmp_u1b;
+ unsigned long flags;
rtlpci->being_init_adapter = true;
+
+ /* Since this function can take a very long time (up to 350 ms)
+ * and can be called with irqs disabled, reenable the irqs
+ * to let the other devices continue being serviced.
+ *
+ * It is safe doing so since our own interrupts will only be enabled
+ * in a subsequent step.
+ */
+ local_save_flags(flags);
+ local_irq_enable();
+
rtlpriv->intf_ops->disable_aspm(hw);
rtstatus = _rtl92ce_init_mac(hw);
if (!rtstatus) {
RT_TRACE(rtlpriv, COMP_ERR, DBG_EMERG, "Init MAC failed\n");
err = 1;
- return err;
+ goto exit;
}
err = rtl92c_download_fw(hw);
@@ -917,7 +929,7 @@ int rtl92ce_hw_init(struct ieee80211_hw *hw)
RT_TRACE(rtlpriv, COMP_ERR, DBG_WARNING,
"Failed to download FW. Init HW without FW now..\n");
err = 1;
- return err;
+ goto exit;
}
rtlhal->last_hmeboxnum = 0;
@@ -978,6 +990,8 @@ int rtl92ce_hw_init(struct ieee80211_hw *hw)
RT_TRACE(rtlpriv, COMP_INIT, DBG_TRACE, "under 1.5V\n");
}
rtl92c_dm_init(hw);
+exit:
+ local_irq_restore(flags);
rtlpci->being_init_adapter = false;
return err;
}
--
1.9.0
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