From: Vinod Koul <vkoul@kernel.org>
To: Russell King <rmk+kernel@armlinux.org.uk>
Cc: Andrew Lunn <andrew@lunn.ch>, Jason Cooper <jason@lakedaemon.net>,
devicetree@vger.kernel.org,
Gregory Clement <gregory.clement@bootlin.com>,
Kishon Vijay Abraham I <kishon@ti.com>,
Rob Herring <robh+dt@kernel.org>,
linux-arm-kernel@lists.infradead.org,
Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Subject: Re: [PATCH 2/2] phy: armada-38x: fix NETA lockup when repeatedly switching speeds
Date: Wed, 1 Jul 2020 12:27:27 +0530 [thread overview]
Message-ID: <20200701065727.GY2599@vkoul-mobl> (raw)
In-Reply-To: <E1jqIlO-0007rX-Tv@rmk-PC.armlinux.org.uk>
On 30-06-20, 17:05, Russell King wrote:
> The mvneta hardware appears to lock up in various random ways when
> repeatedly switching speeds between 1G and 2.5G, which involves
> reprogramming the COMPHY. It is not entirely clear why this happens,
> but best guess is that reprogramming the COMPHY glitches mvneta clocks
> causing the hardware to fail. It seems that rebooting resolves the
> failure, but not down/up cycling the interface alone.
>
> Various other approaches have been tried, such as trying to cleanly
> power down the COMPHY and then take it back through the power up
> initialisation, but this does not seem to help.
>
> It was finally noticed that u-boot's last step when configuring a
> COMPHY for "SGMII" mode was to poke at a register described as
> "GBE_CONFIGURATION_REG", which is undocumented in any external
> documentation. All that we have is the fact that u-boot sets a bit
> corresponding to the "SGMII" lane at the end of COMPHY initialisation.
>
> Experimentation shows that if we clear this bit prior to changing the
> speed, and then set it afterwards, mvneta does not suffer this problem
> on the SolidRun Clearfog when switching speeds between 1G and 2.5G.
>
> This problem was found while script-testing phylink.
>
> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
> ---
> arch/arm/boot/dts/armada-38x.dtsi | 3 +-
lgtm, i need ack for dts parts before I can apply this
> drivers/phy/marvell/phy-armada38x-comphy.c | 45 ++++++++++++++++++----
> 2 files changed, 40 insertions(+), 8 deletions(-)
>
> diff --git a/arch/arm/boot/dts/armada-38x.dtsi b/arch/arm/boot/dts/armada-38x.dtsi
> index e038abc0c6b4..420ae26e846b 100644
> --- a/arch/arm/boot/dts/armada-38x.dtsi
> +++ b/arch/arm/boot/dts/armada-38x.dtsi
> @@ -344,7 +344,8 @@
>
> comphy: phy@18300 {
> compatible = "marvell,armada-380-comphy";
> - reg = <0x18300 0x100>;
> + reg-names = "comphy", "conf";
> + reg = <0x18300 0x100>, <0x18460 4>;
> #address-cells = <1>;
> #size-cells = <0>;
>
> diff --git a/drivers/phy/marvell/phy-armada38x-comphy.c b/drivers/phy/marvell/phy-armada38x-comphy.c
> index 6960dfd8ad8c..0fe408964334 100644
> --- a/drivers/phy/marvell/phy-armada38x-comphy.c
> +++ b/drivers/phy/marvell/phy-armada38x-comphy.c
> @@ -41,6 +41,7 @@ struct a38x_comphy_lane {
>
> struct a38x_comphy {
> void __iomem *base;
> + void __iomem *conf;
> struct device *dev;
> struct a38x_comphy_lane lane[MAX_A38X_COMPHY];
> };
> @@ -54,6 +55,21 @@ static const u8 gbe_mux[MAX_A38X_COMPHY][MAX_A38X_PORTS] = {
> { 0, 0, 3 },
> };
>
> +static void a38x_set_conf(struct a38x_comphy_lane *lane, bool enable)
> +{
> + struct a38x_comphy *priv = lane->priv;
> + u32 conf;
> +
> + if (priv->conf) {
> + conf = readl_relaxed(priv->conf);
> + if (enable)
> + conf |= BIT(lane->port);
> + else
> + conf &= ~BIT(lane->port);
> + writel(conf, priv->conf);
> + }
> +}
> +
> static void a38x_comphy_set_reg(struct a38x_comphy_lane *lane,
> unsigned int offset, u32 mask, u32 value)
> {
> @@ -97,6 +113,7 @@ static int a38x_comphy_set_mode(struct phy *phy, enum phy_mode mode, int sub)
> {
> struct a38x_comphy_lane *lane = phy_get_drvdata(phy);
> unsigned int gen;
> + int ret;
>
> if (mode != PHY_MODE_ETHERNET)
> return -EINVAL;
> @@ -115,13 +132,20 @@ static int a38x_comphy_set_mode(struct phy *phy, enum phy_mode mode, int sub)
> return -EINVAL;
> }
>
> + a38x_set_conf(lane, false);
> +
> a38x_comphy_set_speed(lane, gen, gen);
>
> - return a38x_comphy_poll(lane, COMPHY_STAT1,
> - COMPHY_STAT1_PLL_RDY_TX |
> - COMPHY_STAT1_PLL_RDY_RX,
> - COMPHY_STAT1_PLL_RDY_TX |
> - COMPHY_STAT1_PLL_RDY_RX);
> + ret = a38x_comphy_poll(lane, COMPHY_STAT1,
> + COMPHY_STAT1_PLL_RDY_TX |
> + COMPHY_STAT1_PLL_RDY_RX,
> + COMPHY_STAT1_PLL_RDY_TX |
> + COMPHY_STAT1_PLL_RDY_RX);
> +
> + if (ret == 0)
> + a38x_set_conf(lane, true);
> +
> + return ret;
> }
>
> static const struct phy_ops a38x_comphy_ops = {
> @@ -174,14 +198,21 @@ static int a38x_comphy_probe(struct platform_device *pdev)
> if (!priv)
> return -ENOMEM;
>
> - res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> - base = devm_ioremap_resource(&pdev->dev, res);
> + base = devm_platform_ioremap_resource(pdev, 0);
> if (IS_ERR(base))
> return PTR_ERR(base);
>
> priv->dev = &pdev->dev;
> priv->base = base;
>
> + /* Optional */
> + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "conf");
> + if (res) {
> + priv->conf = devm_ioremap_resource(&pdev->dev, res);
> + if (IS_ERR(priv->conf))
> + return PTR_ERR(priv->conf);
> + }
> +
> for_each_available_child_of_node(pdev->dev.of_node, child) {
> struct phy *phy;
> int ret;
> --
> 2.20.1
--
~Vinod
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next prev parent reply other threads:[~2020-07-01 6:58 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-30 16:04 [PATCH 0/2] Fix Armada 38x mvneta lockups when switching speeds Russell King - ARM Linux admin
2020-06-30 16:05 ` [PATCH 1/2] dt: update Marvell Armada 38x COMPHY binding Russell King
2020-07-09 10:28 ` Russell King - ARM Linux admin
2020-07-15 20:33 ` Rob Herring
2020-06-30 16:05 ` [PATCH 2/2] phy: armada-38x: fix NETA lockup when repeatedly switching speeds Russell King
2020-06-30 16:06 ` Russell King - ARM Linux admin
2020-07-01 6:57 ` Vinod Koul [this message]
2020-07-10 15:19 ` Russell King - ARM Linux admin
2020-07-13 6:18 ` Vinod Koul
2020-07-13 15:36 ` Gregory CLEMENT
2020-07-13 17:21 ` Russell King - ARM Linux admin
2020-07-13 18:07 ` Russell King - ARM Linux admin
2020-07-16 5:46 ` Vinod Koul
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