[OpenWrt-Devel] [PATCH 1/2] ar71xx: fix QCA955X SGMII link loss

John Crispin john at phrozen.org
Wed Aug 8 02:03:11 EDT 2018



On 06/08/18 16:15, David Bauer wrote:
> 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/

nitpick inline

> Based-on-patch-by: Sven Eckelmann <sven.eckelmann at open-mesh.com>
> Signed-off-by: David Bauer <mail at david-bauer.net>
> ---
>   .../files/arch/mips/ath79/mach-fritz450e.c    |  1 +
>   .../include/asm/mach-ath79/ag71xx_platform.h  |  1 +
>   .../net/ethernet/atheros/ag71xx/ag71xx.h      |  2 +
>   .../net/ethernet/atheros/ag71xx/ag71xx_main.c | 79 +++++++++++++++++++
>   .../940-qca955x-add-more-registers.patch      | 44 +++++++++++
>   5 files changed, 127 insertions(+)
>   create mode 100644 target/linux/ar71xx/patches-4.9/940-qca955x-add-more-registers.patch
>
> diff --git a/target/linux/ar71xx/files/arch/mips/ath79/mach-fritz450e.c b/target/linux/ar71xx/files/arch/mips/ath79/mach-fritz450e.c
> index ee0a185304..e48ddd65e7 100644
> --- a/target/linux/ar71xx/files/arch/mips/ath79/mach-fritz450e.c
> +++ b/target/linux/ar71xx/files/arch/mips/ath79/mach-fritz450e.c
> @@ -155,6 +155,7 @@ static void __init fritz450E_setup(void) {
>   	ath79_eth0_data.mii_bus_dev = &ath79_mdio1_device.dev;
>   	ath79_eth0_data.phy_if_mode = PHY_INTERFACE_MODE_SGMII;
>   	ath79_eth0_data.phy_mask = BIT(FRITZ450E_PHY_ADDRESS);
> +	ath79_eth0_data.enable_sgmii_fixup = 1;
>   	ath79_eth0_pll_data.pll_1000 = 0x03000000;
>   	ath79_eth0_pll_data.pll_100 = 0x00000101;
>   	ath79_eth0_pll_data.pll_10 = 0x00001313;
> diff --git a/target/linux/ar71xx/files/arch/mips/include/asm/mach-ath79/ag71xx_platform.h b/target/linux/ar71xx/files/arch/mips/include/asm/mach-ath79/ag71xx_platform.h
> index c4c3a6d44c..e476d57e45 100644
> --- a/target/linux/ar71xx/files/arch/mips/include/asm/mach-ath79/ag71xx_platform.h
> +++ b/target/linux/ar71xx/files/arch/mips/include/asm/mach-ath79/ag71xx_platform.h
> @@ -37,6 +37,7 @@ struct ag71xx_platform_data {
>   	u8		is_ar724x:1;
>   	u8		has_ar8216:1;
>   	u8		use_flow_control:1;
> +	u8		enable_sgmii_fixup:1;
>   	u8		disable_inline_checksum_engine:1;
>   
>   	struct ag71xx_switch_platform_data *switch_data;
> 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..d89579298f 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
this is a c++ style comment ....

> +	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);
> diff --git a/target/linux/ar71xx/patches-4.9/940-qca955x-add-more-registers.patch b/target/linux/ar71xx/patches-4.9/940-qca955x-add-more-registers.patch
> new file mode 100644
> index 0000000000..97400e3ec8
> --- /dev/null
> +++ b/target/linux/ar71xx/patches-4.9/940-qca955x-add-more-registers.patch
> @@ -0,0 +1,44 @@
> +Index: linux-4.9.111/arch/mips/include/asm/mach-ath79/ar71xx_regs.h
> +===================================================================
> +--- linux-4.9.111.orig/arch/mips/include/asm/mach-ath79/ar71xx_regs.h
> ++++ linux-4.9.111/arch/mips/include/asm/mach-ath79/ar71xx_regs.h
> +@@ -134,7 +134,7 @@
> + #define QCA955X_PCI_CTRL_SIZE	0x100
> +
> + #define QCA955X_GMAC_BASE	(AR71XX_APB_BASE + 0x00070000)
> +-#define QCA955X_GMAC_SIZE	0x40
> ++#define QCA955X_GMAC_SIZE	0x64
> + #define QCA955X_WMAC_BASE	(AR71XX_APB_BASE + 0x00100000)
> + #define QCA955X_WMAC_SIZE	0x20000
> + #define QCA955X_EHCI0_BASE	0x1b000000
> +@@ -1269,7 +1269,11 @@
> +  */
> +
> + #define QCA955X_GMAC_REG_ETH_CFG	0x00
> ++#define QCA955X_GMAC_REG_SGMII_RESET	0x14
> + #define QCA955X_GMAC_REG_SGMII_SERDES	0x18
> ++#define QCA955X_GMAC_REG_MR_AN_CONTROL	0x1c
> ++#define QCA955X_GMAC_REG_MR_AN_STATUS	0x20
> ++#define QCA955X_GMAC_REG_SGMII_DEBUG	0x58
> +
> + #define QCA955X_ETH_CFG_RGMII_EN	BIT(0)
> + #define QCA955X_ETH_CFG_MII_GE0		BIT(1)
> +@@ -1291,6 +1295,18 @@
> + #define QCA955X_ETH_CFG_TXE_DELAY_MASK	0x3
> + #define QCA955X_ETH_CFG_TXE_DELAY_SHIFT	20
> +
> ++#define QCA955X_SGMII_RESET_RX_CLK_N_RESET	0x0
> ++#define QCA955X_SGMII_RESET_RX_CLK_N		BIT(0)
> ++#define QCA955X_SGMII_RESET_TX_CLK_N		BIT(1)
> ++#define QCA955X_SGMII_RESET_RX_125M_N		BIT(2)
> ++#define QCA955X_SGMII_RESET_TX_125M_N		BIT(3)
> ++#define QCA955X_SGMII_RESET_HW_RX_125M_N	BIT(4)
> ++
> ++#define QCA955X_MR_AN_CONTROL_PHY_RESET	BIT(15)
> ++#define QCA955X_MR_AN_CONTROL_AN_ENABLE	BIT(12)
> ++
> ++#define QCA955X_MR_AN_STATUS_AN_ABILITY	BIT(3)
> ++
> + #define QCA955X_SGMII_SERDES_LOCK_DETECT_STATUS	BIT(15)
> + #define QCA955X_SGMII_SERDES_RES_CALIBRATION_SHIFT 23
> + #define QCA955X_SGMII_SERDES_RES_CALIBRATION_MASK 0xf


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