From 3444638a05abf7456bb86823c33d651183bd137e Mon Sep 17 00:00:00 2001 From: David Bauer Date: Mon, 6 Aug 2018 16:15:04 +0200 Subject: ar71xx: fix QCA955X SGMII link loss The QCA955X is affected by a hardware bug which causes link-loss of the SGMII link between SoC and PHY. This happens on change of link-state or speed. It is not really known what causes this bug. It definitely occurs when using a AR8033 Gigabit Ethernet PHY. Qualcomm solves this Bug in a similar fashion. We need to apply the fix on a per-device base via platform-data as performing the fixup work will break connectivity in case the SGMII interface is connected to a Switch. This bug was first proposed to be fixed by Sven Eckelmann in 2016. https://patchwork.ozlabs.org/patch/604782/ Based-on-patch-by: Sven Eckelmann Signed-off-by: David Bauer (cherry picked from commit f4f99ec9737c653815268f2efad0210caaa32e2d) --- .../drivers/net/ethernet/atheros/ag71xx/ag71xx.h | 2 + .../net/ethernet/atheros/ag71xx/ag71xx_main.c | 79 ++++++++++++++++++++++ 2 files changed, 81 insertions(+) (limited to 'target/linux/ar71xx/files/drivers') diff --git a/target/linux/ar71xx/files/drivers/net/ethernet/atheros/ag71xx/ag71xx.h b/target/linux/ar71xx/files/drivers/net/ethernet/atheros/ag71xx/ag71xx.h index 77ee5b36ec..2d9a865043 100644 --- a/target/linux/ar71xx/files/drivers/net/ethernet/atheros/ag71xx/ag71xx.h +++ b/target/linux/ar71xx/files/drivers/net/ethernet/atheros/ag71xx/ag71xx.h @@ -66,6 +66,8 @@ #define AG71XX_TX_RING_SIZE_MAX 128 #define AG71XX_RX_RING_SIZE_MAX 256 +#define QCA955X_SGMII_LINK_WAR_MAX_TRY 10 + #ifdef CONFIG_AG71XX_DEBUG #define DBG(fmt, args...) pr_debug(fmt, ## args) #else diff --git a/target/linux/ar71xx/files/drivers/net/ethernet/atheros/ag71xx/ag71xx_main.c b/target/linux/ar71xx/files/drivers/net/ethernet/atheros/ag71xx/ag71xx_main.c index 54ec8e67b3..109335ef0f 100644 --- a/target/linux/ar71xx/files/drivers/net/ethernet/atheros/ag71xx/ag71xx_main.c +++ b/target/linux/ar71xx/files/drivers/net/ethernet/atheros/ag71xx/ag71xx_main.c @@ -31,6 +31,7 @@ MODULE_PARM_DESC(msg_level, "Message level (-1=defaults,0=none,...,16=all)"); #define ETH_SWITCH_HEADER_LEN 2 static int ag71xx_tx_packets(struct ag71xx *ag, bool flush); +static void ag71xx_qca955x_sgmii_init(void); static inline unsigned int ag71xx_max_frame_len(unsigned int mtu) { @@ -610,6 +611,9 @@ __ag71xx_link_adjust(struct ag71xx *ag, bool update) if (update && pdata->set_speed) pdata->set_speed(ag->speed); + if (update && pdata->enable_sgmii_fixup) + ag71xx_qca955x_sgmii_init(); + ag71xx_wr(ag, AG71XX_REG_MAC_CFG2, cfg2); ag71xx_wr(ag, AG71XX_REG_FIFO_CFG5, fifo5); ag71xx_wr(ag, AG71XX_REG_MAC_IFCTL, ifctl); @@ -913,6 +917,81 @@ static void ag71xx_tx_timeout(struct net_device *dev) schedule_delayed_work(&ag->restart_work, 1); } +static void ag71xx_bit_set(void __iomem *reg, u32 bit) +{ + u32 val = __raw_readl(reg) | bit; + __raw_writel(val, reg); + __raw_readl(reg); +} + +static void ag71xx_bit_clear(void __iomem *reg, u32 bit) +{ + u32 val = __raw_readl(reg) & ~bit; + __raw_writel(val, reg); + __raw_readl(reg); +} + +static void ag71xx_qca955x_sgmii_init() +{ + void __iomem *gmac_base; + u32 mr_an_status, sgmii_status; + u8 tries = 0; + + gmac_base = ioremap_nocache(QCA955X_GMAC_BASE, QCA955X_GMAC_SIZE); + + if (!gmac_base) + goto sgmii_out; + + mr_an_status = __raw_readl(gmac_base + QCA955X_GMAC_REG_MR_AN_STATUS); + if (!(mr_an_status & QCA955X_MR_AN_STATUS_AN_ABILITY)) + goto sgmii_out; + + __raw_writel(QCA955X_SGMII_RESET_RX_CLK_N_RESET , + gmac_base + QCA955X_GMAC_REG_SGMII_RESET); + __raw_readl(gmac_base + QCA955X_GMAC_REG_SGMII_RESET); + udelay(10); + + /* Init sequence */ + ag71xx_bit_set(gmac_base + QCA955X_GMAC_REG_SGMII_RESET, + QCA955X_SGMII_RESET_HW_RX_125M_N); + udelay(10); + + ag71xx_bit_set(gmac_base + QCA955X_GMAC_REG_SGMII_RESET, + QCA955X_SGMII_RESET_RX_125M_N); + udelay(10); + + ag71xx_bit_set(gmac_base + QCA955X_GMAC_REG_SGMII_RESET, + QCA955X_SGMII_RESET_TX_125M_N); + udelay(10); + + ag71xx_bit_set(gmac_base + QCA955X_GMAC_REG_SGMII_RESET, + QCA955X_SGMII_RESET_RX_CLK_N); + udelay(10); + + ag71xx_bit_set(gmac_base + QCA955X_GMAC_REG_SGMII_RESET, + QCA955X_SGMII_RESET_TX_CLK_N); + udelay(10); + + do { + ag71xx_bit_set(gmac_base + QCA955X_GMAC_REG_MR_AN_CONTROL, + QCA955X_MR_AN_CONTROL_PHY_RESET | + QCA955X_MR_AN_CONTROL_AN_ENABLE); + udelay(100); + ag71xx_bit_clear(gmac_base + QCA955X_GMAC_REG_MR_AN_CONTROL, + QCA955X_MR_AN_CONTROL_PHY_RESET); + mdelay(10); + sgmii_status = __raw_readl(gmac_base + QCA955X_GMAC_REG_SGMII_DEBUG) & 0xF; + + if (tries++ >= QCA955X_SGMII_LINK_WAR_MAX_TRY) { + pr_warn("ag71xx: max retries for SGMII fixup exceeded!\n"); + break; + } + } while (!(sgmii_status == 0xf || sgmii_status == 0x10)); + +sgmii_out: + iounmap(gmac_base); +} + static void ag71xx_restart_work_func(struct work_struct *work) { struct ag71xx *ag = container_of(work, struct ag71xx, restart_work.work); -- cgit v1.2.3