From 21b39ddb5bb2294fe64fbd29045591fe0707825f Mon Sep 17 00:00:00 2001 From: Troy Tan Date: Tue, 20 Jan 2015 11:01:26 -0600 Subject: [PATCH] rtlwifi: rtl8192ee: Fix DMA stalls There are instances where the DMA engine stalls. The new code detects such stalls and restarts DMA without needing a power reset. Signed-off-by: Troy Tan Signed-off-by: Larry Finger Cc: Stable [3.18] Signed-off-by: Kalle Valo --- drivers/net/wireless/rtlwifi/rtl8192ee/hw.c | 140 +++++++++++++++++++ drivers/net/wireless/rtlwifi/rtl8192ee/reg.h | 2 + 2 files changed, 142 insertions(+) diff --git a/drivers/net/wireless/rtlwifi/rtl8192ee/hw.c b/drivers/net/wireless/rtlwifi/rtl8192ee/hw.c index 3c27ec2c7b5a..b461b3128da5 100644 --- a/drivers/net/wireless/rtlwifi/rtl8192ee/hw.c +++ b/drivers/net/wireless/rtlwifi/rtl8192ee/hw.c @@ -1137,6 +1137,139 @@ void rtl92ee_enable_hw_security_config(struct ieee80211_hw *hw) rtlpriv->cfg->ops->set_hw_reg(hw, HW_VAR_WPA_CONFIG, &sec_reg_value); } +static bool _rtl8192ee_check_pcie_dma_hang(struct rtl_priv *rtlpriv) +{ + u8 tmp; + + /* write reg 0x350 Bit[26]=1. Enable debug port. */ + tmp = rtl_read_byte(rtlpriv, REG_BACKDOOR_DBI_DATA + 3); + if (!(tmp & BIT(2))) { + rtl_write_byte(rtlpriv, REG_BACKDOOR_DBI_DATA + 3, + tmp | BIT(2)); + mdelay(100); /* Suggested by DD Justin_tsai. */ + } + + /* read reg 0x350 Bit[25] if 1 : RX hang + * read reg 0x350 Bit[24] if 1 : TX hang + */ + tmp = rtl_read_byte(rtlpriv, REG_BACKDOOR_DBI_DATA + 3); + if ((tmp & BIT(0)) || (tmp & BIT(1))) { + RT_TRACE(rtlpriv, COMP_INIT, DBG_LOUD, + "CheckPcieDMAHang8192EE(): true!!\n"); + return true; + } + return false; +} + +static void _rtl8192ee_reset_pcie_interface_dma(struct rtl_priv *rtlpriv, + bool mac_power_on) +{ + u8 tmp; + bool release_mac_rx_pause; + u8 backup_pcie_dma_pause; + + RT_TRACE(rtlpriv, COMP_INIT, DBG_LOUD, + "ResetPcieInterfaceDMA8192EE()\n"); + + /* Revise Note: Follow the document "PCIe RX DMA Hang Reset Flow_v03" + * released by SD1 Alan. + */ + + /* 1. disable register write lock + * write 0x1C bit[1:0] = 2'h0 + * write 0xCC bit[2] = 1'b1 + */ + tmp = rtl_read_byte(rtlpriv, REG_RSV_CTRL); + tmp &= ~(BIT(1) | BIT(0)); + rtl_write_byte(rtlpriv, REG_RSV_CTRL, tmp); + tmp = rtl_read_byte(rtlpriv, REG_PMC_DBG_CTRL2); + tmp |= BIT(2); + rtl_write_byte(rtlpriv, REG_PMC_DBG_CTRL2, tmp); + + /* 2. Check and pause TRX DMA + * write 0x284 bit[18] = 1'b1 + * write 0x301 = 0xFF + */ + tmp = rtl_read_byte(rtlpriv, REG_RXDMA_CONTROL); + if (tmp & BIT(2)) { + /* Already pause before the function for another reason. */ + release_mac_rx_pause = false; + } else { + rtl_write_byte(rtlpriv, REG_RXDMA_CONTROL, (tmp | BIT(2))); + release_mac_rx_pause = true; + } + + backup_pcie_dma_pause = rtl_read_byte(rtlpriv, REG_PCIE_CTRL_REG + 1); + if (backup_pcie_dma_pause != 0xFF) + rtl_write_byte(rtlpriv, REG_PCIE_CTRL_REG + 1, 0xFF); + + if (mac_power_on) { + /* 3. reset TRX function + * write 0x100 = 0x00 + */ + rtl_write_byte(rtlpriv, REG_CR, 0); + } + + /* 4. Reset PCIe DMA + * write 0x003 bit[0] = 0 + */ + tmp = rtl_read_byte(rtlpriv, REG_SYS_FUNC_EN + 1); + tmp &= ~(BIT(0)); + rtl_write_byte(rtlpriv, REG_SYS_FUNC_EN + 1, tmp); + + /* 5. Enable PCIe DMA + * write 0x003 bit[0] = 1 + */ + tmp = rtl_read_byte(rtlpriv, REG_SYS_FUNC_EN + 1); + tmp |= BIT(0); + rtl_write_byte(rtlpriv, REG_SYS_FUNC_EN + 1, tmp); + + if (mac_power_on) { + /* 6. enable TRX function + * write 0x100 = 0xFF + */ + rtl_write_byte(rtlpriv, REG_CR, 0xFF); + + /* We should init LLT & RQPN and + * prepare Tx/Rx descrptor address later + * because MAC function is reset. + */ + } + + /* 7. Restore PCIe autoload down bit + * write 0xF8 bit[17] = 1'b1 + */ + tmp = rtl_read_byte(rtlpriv, REG_MAC_PHY_CTRL_NORMAL + 2); + tmp |= BIT(1); + rtl_write_byte(rtlpriv, REG_MAC_PHY_CTRL_NORMAL + 2, tmp); + + /* In MAC power on state, BB and RF maybe in ON state, + * if we release TRx DMA here + * it will cause packets to be started to Tx/Rx, + * so we release Tx/Rx DMA later. + */ + if (!mac_power_on) { + /* 8. release TRX DMA + * write 0x284 bit[18] = 1'b0 + * write 0x301 = 0x00 + */ + if (release_mac_rx_pause) { + tmp = rtl_read_byte(rtlpriv, REG_RXDMA_CONTROL); + rtl_write_byte(rtlpriv, REG_RXDMA_CONTROL, + (tmp & (~BIT(2)))); + } + rtl_write_byte(rtlpriv, REG_PCIE_CTRL_REG + 1, + backup_pcie_dma_pause); + } + + /* 9. lock system register + * write 0xCC bit[2] = 1'b0 + */ + tmp = rtl_read_byte(rtlpriv, REG_PMC_DBG_CTRL2); + tmp &= ~(BIT(2)); + rtl_write_byte(rtlpriv, REG_PMC_DBG_CTRL2, tmp); +} + int rtl92ee_hw_init(struct ieee80211_hw *hw) { struct rtl_priv *rtlpriv = rtl_priv(hw); @@ -1162,6 +1295,13 @@ int rtl92ee_hw_init(struct ieee80211_hw *hw) rtlhal->fw_ps_state = FW_PS_STATE_ALL_ON_92E; } + if (_rtl8192ee_check_pcie_dma_hang(rtlpriv)) { + RT_TRACE(rtlpriv, COMP_INIT, DBG_DMESG, "92ee dma hang!\n"); + _rtl8192ee_reset_pcie_interface_dma(rtlpriv, + rtlhal->mac_func_enable); + rtlhal->mac_func_enable = false; + } + rtstatus = _rtl92ee_init_mac(hw); rtl_write_byte(rtlpriv, 0x577, 0x03); diff --git a/drivers/net/wireless/rtlwifi/rtl8192ee/reg.h b/drivers/net/wireless/rtlwifi/rtl8192ee/reg.h index 3f2a9596e7cd..1eaa1fab550d 100644 --- a/drivers/net/wireless/rtlwifi/rtl8192ee/reg.h +++ b/drivers/net/wireless/rtlwifi/rtl8192ee/reg.h @@ -77,9 +77,11 @@ #define REG_HIMRE 0x00B8 #define REG_HISRE 0x00BC +#define REG_PMC_DBG_CTRL2 0x00CC #define REG_EFUSE_ACCESS 0x00CF #define REG_HPON_FSM 0x00EC #define REG_SYS_CFG1 0x00F0 +#define REG_MAC_PHY_CTRL_NORMAL 0x00F8 #define REG_SYS_CFG2 0x00FC #define REG_CR 0x0100 -- 2.20.1