From 6198c722019774d38018457a8bfb9ba3ed8c931e Mon Sep 17 00:00:00 2001 From: Tobias Waldekranz Date: Tue, 18 Jan 2022 22:50:50 +0100 Subject: [PATCH 1/4] net/fsl: xgmac_mdio: Add workaround for erratum A-009885 Once an MDIO read transaction is initiated, we must read back the data register within 16 MDC cycles after the transaction completes. Outside of this window, reads may return corrupt data. Therefore, disable local interrupts in the critical section, to maximize the probability that we can satisfy this requirement. Fixes: d55ad2967d89 ("powerpc/mpc85xx: Create dts components for the FSL QorIQ DPAA FMan") Signed-off-by: Tobias Waldekranz Reviewed-by: Andrew Lunn Signed-off-by: Jakub Kicinski --- drivers/net/ethernet/freescale/xgmac_mdio.c | 25 ++++++++++++++++----- 1 file changed, 19 insertions(+), 6 deletions(-) diff --git a/drivers/net/ethernet/freescale/xgmac_mdio.c b/drivers/net/ethernet/freescale/xgmac_mdio.c index 5b8b9bcf41a2..bf566ac3195b 100644 --- a/drivers/net/ethernet/freescale/xgmac_mdio.c +++ b/drivers/net/ethernet/freescale/xgmac_mdio.c @@ -51,6 +51,7 @@ struct tgec_mdio_controller { struct mdio_fsl_priv { struct tgec_mdio_controller __iomem *mdio_base; bool is_little_endian; + bool has_a009885; bool has_a011043; }; @@ -186,10 +187,10 @@ static int xgmac_mdio_read(struct mii_bus *bus, int phy_id, int regnum) { struct mdio_fsl_priv *priv = (struct mdio_fsl_priv *)bus->priv; struct tgec_mdio_controller __iomem *regs = priv->mdio_base; + unsigned long flags; uint16_t dev_addr; uint32_t mdio_stat; uint32_t mdio_ctl; - uint16_t value; int ret; bool endian = priv->is_little_endian; @@ -221,12 +222,18 @@ static int xgmac_mdio_read(struct mii_bus *bus, int phy_id, int regnum) return ret; } + if (priv->has_a009885) + /* Once the operation completes, i.e. MDIO_STAT_BSY clears, we + * must read back the data register within 16 MDC cycles. + */ + local_irq_save(flags); + /* Initiate the read */ xgmac_write32(mdio_ctl | MDIO_CTL_READ, ®s->mdio_ctl, endian); ret = xgmac_wait_until_done(&bus->dev, regs, endian); if (ret) - return ret; + goto irq_restore; /* Return all Fs if nothing was there */ if ((xgmac_read32(®s->mdio_stat, endian) & MDIO_STAT_RD_ER) && @@ -234,13 +241,17 @@ static int xgmac_mdio_read(struct mii_bus *bus, int phy_id, int regnum) dev_dbg(&bus->dev, "Error while reading PHY%d reg at %d.%hhu\n", phy_id, dev_addr, regnum); - return 0xffff; + ret = 0xffff; + } else { + ret = xgmac_read32(®s->mdio_data, endian) & 0xffff; + dev_dbg(&bus->dev, "read %04x\n", ret); } - value = xgmac_read32(®s->mdio_data, endian) & 0xffff; - dev_dbg(&bus->dev, "read %04x\n", value); +irq_restore: + if (priv->has_a009885) + local_irq_restore(flags); - return value; + return ret; } static int xgmac_mdio_probe(struct platform_device *pdev) @@ -287,6 +298,8 @@ static int xgmac_mdio_probe(struct platform_device *pdev) priv->is_little_endian = device_property_read_bool(&pdev->dev, "little-endian"); + priv->has_a009885 = device_property_read_bool(&pdev->dev, + "fsl,erratum-a009885"); priv->has_a011043 = device_property_read_bool(&pdev->dev, "fsl,erratum-a011043"); From ea11fc509ff26039046744d1bdfdf2747dda558c Mon Sep 17 00:00:00 2001 From: Tobias Waldekranz Date: Tue, 18 Jan 2022 22:50:51 +0100 Subject: [PATCH 2/4] dt-bindings: net: Document fsl,erratum-a009885 Update FMan binding documentation with the newly added workaround for erratum A-009885. Signed-off-by: Tobias Waldekranz Reviewed-by: Andrew Lunn Signed-off-by: Jakub Kicinski --- Documentation/devicetree/bindings/net/fsl-fman.txt | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/Documentation/devicetree/bindings/net/fsl-fman.txt b/Documentation/devicetree/bindings/net/fsl-fman.txt index c00fb0d22c7b..020337f3c05f 100644 --- a/Documentation/devicetree/bindings/net/fsl-fman.txt +++ b/Documentation/devicetree/bindings/net/fsl-fman.txt @@ -410,6 +410,15 @@ PROPERTIES The settings and programming routines for internal/external MDIO are different. Must be included for internal MDIO. +- fsl,erratum-a009885 + Usage: optional + Value type: + Definition: Indicates the presence of the A009885 + erratum describing that the contents of MDIO_DATA may + become corrupt unless it is read within 16 MDC cycles + of MDIO_CFG[BSY] being cleared, when performing an + MDIO read operation. + - fsl,erratum-a011043 Usage: optional Value type: From 0d375d610fa96524e2ee2b46830a46a7bfa92a9f Mon Sep 17 00:00:00 2001 From: Tobias Waldekranz Date: Tue, 18 Jan 2022 22:50:52 +0100 Subject: [PATCH 3/4] powerpc/fsl/dts: Enable WA for erratum A-009885 on fman3l MDIO buses This block is used in (at least) T1024 and T1040, including their variants like T1023 etc. Fixes: d55ad2967d89 ("powerpc/mpc85xx: Create dts components for the FSL QorIQ DPAA FMan") Signed-off-by: Tobias Waldekranz Signed-off-by: Jakub Kicinski --- arch/powerpc/boot/dts/fsl/qoriq-fman3l-0.dtsi | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/powerpc/boot/dts/fsl/qoriq-fman3l-0.dtsi b/arch/powerpc/boot/dts/fsl/qoriq-fman3l-0.dtsi index c90702b04a53..48e5cd61599c 100644 --- a/arch/powerpc/boot/dts/fsl/qoriq-fman3l-0.dtsi +++ b/arch/powerpc/boot/dts/fsl/qoriq-fman3l-0.dtsi @@ -79,6 +79,7 @@ fman0: fman@400000 { #size-cells = <0>; compatible = "fsl,fman-memac-mdio", "fsl,fman-xmdio"; reg = <0xfc000 0x1000>; + fsl,erratum-a009885; }; xmdio0: mdio@fd000 { @@ -86,6 +87,7 @@ fman0: fman@400000 { #size-cells = <0>; compatible = "fsl,fman-memac-mdio", "fsl,fman-xmdio"; reg = <0xfd000 0x1000>; + fsl,erratum-a009885; }; }; From 3f7c239c7844d2044ed399399d97a5f1c6008e1b Mon Sep 17 00:00:00 2001 From: Tobias Waldekranz Date: Tue, 18 Jan 2022 22:50:53 +0100 Subject: [PATCH 4/4] net/fsl: xgmac_mdio: Fix incorrect iounmap when removing module As reported by sparse: In the remove path, the driver would attempt to unmap its own priv pointer - instead of the io memory that it mapped in probe. Fixes: 9f35a7342cff ("net/fsl: introduce Freescale 10G MDIO driver") Signed-off-by: Tobias Waldekranz Reviewed-by: Andrew Lunn Signed-off-by: Jakub Kicinski --- drivers/net/ethernet/freescale/xgmac_mdio.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/freescale/xgmac_mdio.c b/drivers/net/ethernet/freescale/xgmac_mdio.c index bf566ac3195b..266e562bd67a 100644 --- a/drivers/net/ethernet/freescale/xgmac_mdio.c +++ b/drivers/net/ethernet/freescale/xgmac_mdio.c @@ -331,9 +331,10 @@ err_ioremap: static int xgmac_mdio_remove(struct platform_device *pdev) { struct mii_bus *bus = platform_get_drvdata(pdev); + struct mdio_fsl_priv *priv = bus->priv; mdiobus_unregister(bus); - iounmap(bus->priv); + iounmap(priv->mdio_base); mdiobus_free(bus); return 0;