[PATCHv6 RFT] net: fec: Ensure clocks are enabled while using mdio bus
From: Andrew Lunn <andrew@lunn.ch>
Date: 2015-07-25 20:44:55
When a switch is attached to the mdio bus, the mdio bus can be used
while the interface is not open. If the IPG clock is not enabled, MDIO
reads/writes will simply time out.
Add support for runtime PM to control this clock. Enable/disable this
clock using runtime PM, with open()/close() and mdio read()/write()
function triggering runtime PM operations. Since PM is optional, the
IPG clock is enabled at probe and is no longer modified by
fec_enet_clk_enable(), thus if PM is not enabled in the kernel, it is
guaranteed the clock is running when MDIO operations are performed.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Cc: <redacted>
Cc: <redacted>
Cc: <redacted>
---
v5 was accepted and then reverted, because it broke imx6. Lucas Stach
debugged what was going wrong and provided a patch. Thanks Lucas. This
has been squashed into v6.
It would be good if this version had more testing on various platforms
before it is accepted. If you reported a problem last time, please do
test and send a Tested-by:
I'm out the office for a week starting tomorrow.
Thanks
Andrew
v6: Move the runtime PM setup before the mdio probe.
Also move autosuspend init calls before runtime_pm_enable() so
that the RPM callbacks aren't invoked several times during the
probe function.
---
drivers/net/ethernet/freescale/fec_main.c | 89 ++++++++++++++++++++++++++-----
1 file changed, 76 insertions(+), 13 deletions(-)
diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index 1f89c59b4353..349365d85b92 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c@@ -24,6 +24,7 @@ #include <linux/module.h> #include <linux/kernel.h> #include <linux/string.h> +#include <linux/pm_runtime.h> #include <linux/ptrace.h> #include <linux/errno.h> #include <linux/ioport.h>
@@ -77,6 +78,7 @@ static void fec_enet_itr_coal_init(struct net_device *ndev); #define FEC_ENET_RAEM_V 0x8 #define FEC_ENET_RAFL_V 0x8 #define FEC_ENET_OPD_V 0xFFF0 +#define FEC_MDIO_PM_TIMEOUT 100 /* ms */ static struct platform_device_id fec_devtype[] = { {
@@ -1767,7 +1769,13 @@ static void fec_enet_adjust_link(struct net_device *ndev) static int fec_enet_mdio_read(struct mii_bus *bus, int mii_id, int regnum) { struct fec_enet_private *fep = bus->priv; + struct device *dev = &fep->pdev->dev; unsigned long time_left; + int ret = 0; + + ret = pm_runtime_get_sync(dev); + if (IS_ERR_VALUE(ret)) + return ret; fep->mii_timeout = 0; init_completion(&fep->mdio_done);
@@ -1783,18 +1791,30 @@ static int fec_enet_mdio_read(struct mii_bus *bus, int mii_id, int regnum) if (time_left == 0) { fep->mii_timeout = 1; netdev_err(fep->netdev, "MDIO read timeout\n"); - return -ETIMEDOUT; + ret = -ETIMEDOUT; + goto out; } - /* return value */ - return FEC_MMFR_DATA(readl(fep->hwp + FEC_MII_DATA)); + ret = FEC_MMFR_DATA(readl(fep->hwp + FEC_MII_DATA)); + +out: + pm_runtime_mark_last_busy(dev); + pm_runtime_put_autosuspend(dev); + + return ret; } static int fec_enet_mdio_write(struct mii_bus *bus, int mii_id, int regnum, u16 value) { struct fec_enet_private *fep = bus->priv; + struct device *dev = &fep->pdev->dev; unsigned long time_left; + int ret = 0; + + ret = pm_runtime_get_sync(dev); + if (IS_ERR_VALUE(ret)) + return ret; fep->mii_timeout = 0; init_completion(&fep->mdio_done);
@@ -1811,10 +1831,13 @@ static int fec_enet_mdio_write(struct mii_bus *bus, int mii_id, int regnum, if (time_left == 0) { fep->mii_timeout = 1; netdev_err(fep->netdev, "MDIO write timeout\n"); - return -ETIMEDOUT; + ret = -ETIMEDOUT; } - return 0; + pm_runtime_mark_last_busy(dev); + pm_runtime_put_autosuspend(dev); + + return ret; } static int fec_enet_clk_enable(struct net_device *ndev, bool enable)
@@ -1826,9 +1849,6 @@ static int fec_enet_clk_enable(struct net_device *ndev, bool enable) ret = clk_prepare_enable(fep->clk_ahb); if (ret) return ret; - ret = clk_prepare_enable(fep->clk_ipg); - if (ret) - goto failed_clk_ipg; if (fep->clk_enet_out) { ret = clk_prepare_enable(fep->clk_enet_out); if (ret)
@@ -1852,7 +1872,6 @@ static int fec_enet_clk_enable(struct net_device *ndev, bool enable) } } else { clk_disable_unprepare(fep->clk_ahb); - clk_disable_unprepare(fep->clk_ipg); if (fep->clk_enet_out) clk_disable_unprepare(fep->clk_enet_out); if (fep->clk_ptp) {
@@ -1874,8 +1893,6 @@ failed_clk_ptp: if (fep->clk_enet_out) clk_disable_unprepare(fep->clk_enet_out); failed_clk_enet_out: - clk_disable_unprepare(fep->clk_ipg); -failed_clk_ipg: clk_disable_unprepare(fep->clk_ahb); return ret;
@@ -2847,10 +2864,14 @@ fec_enet_open(struct net_device *ndev) struct fec_enet_private *fep = netdev_priv(ndev); int ret; + ret = pm_runtime_get_sync(&fep->pdev->dev); + if (IS_ERR_VALUE(ret)) + return ret; + pinctrl_pm_select_default_state(&fep->pdev->dev); ret = fec_enet_clk_enable(ndev, true); if (ret) - return ret; + goto clk_enable; /* I should reset the ring buffers here, but I don't yet know * a simple way to do that.
@@ -2881,6 +2902,9 @@ err_enet_mii_probe: fec_enet_free_buffers(ndev); err_enet_alloc: fec_enet_clk_enable(ndev, false); +clk_enable: + pm_runtime_mark_last_busy(&fep->pdev->dev); + pm_runtime_put_autosuspend(&fep->pdev->dev); pinctrl_pm_select_sleep_state(&fep->pdev->dev); return ret; }
@@ -2903,6 +2927,9 @@ fec_enet_close(struct net_device *ndev) fec_enet_clk_enable(ndev, false); pinctrl_pm_select_sleep_state(&fep->pdev->dev); + pm_runtime_mark_last_busy(&fep->pdev->dev); + pm_runtime_put_autosuspend(&fep->pdev->dev); + fec_enet_free_buffers(ndev); return 0;
@@ -3388,6 +3415,10 @@ fec_probe(struct platform_device *pdev) if (ret) goto failed_clk; + ret = clk_prepare_enable(fep->clk_ipg); + if (ret) + goto failed_clk_ipg; + fep->reg_phy = devm_regulator_get(&pdev->dev, "phy"); if (!IS_ERR(fep->reg_phy)) { ret = regulator_enable(fep->reg_phy);
@@ -3400,6 +3431,11 @@ fec_probe(struct platform_device *pdev) fep->reg_phy = NULL; } + pm_runtime_set_autosuspend_delay(&pdev->dev, FEC_MDIO_PM_TIMEOUT); + pm_runtime_use_autosuspend(&pdev->dev); + pm_runtime_set_active(&pdev->dev); + pm_runtime_enable(&pdev->dev); + fec_reset_phy(pdev); if (fep->bufdesc_ex)
@@ -3447,6 +3483,10 @@ fec_probe(struct platform_device *pdev) fep->rx_copybreak = COPYBREAK_DEFAULT; INIT_WORK(&fep->tx_timeout_work, fec_enet_timeout_work); + + pm_runtime_mark_last_busy(&pdev->dev); + pm_runtime_put_autosuspend(&pdev->dev); + return 0; failed_register:
@@ -3457,6 +3497,8 @@ failed_init: if (fep->reg_phy) regulator_disable(fep->reg_phy); failed_regulator: + clk_disable_unprepare(fep->clk_ipg); +failed_clk_ipg: fec_enet_clk_enable(ndev, false); failed_clk: failed_phy:
@@ -3568,7 +3610,28 @@ failed_clk: return ret; } -static SIMPLE_DEV_PM_OPS(fec_pm_ops, fec_suspend, fec_resume); +static int __maybe_unused fec_runtime_suspend(struct device *dev) +{ + struct net_device *ndev = dev_get_drvdata(dev); + struct fec_enet_private *fep = netdev_priv(ndev); + + clk_disable_unprepare(fep->clk_ipg); + + return 0; +} + +static int __maybe_unused fec_runtime_resume(struct device *dev) +{ + struct net_device *ndev = dev_get_drvdata(dev); + struct fec_enet_private *fep = netdev_priv(ndev); + + return clk_prepare_enable(fep->clk_ipg); +} + +static const struct dev_pm_ops fec_pm_ops = { + SET_SYSTEM_SLEEP_PM_OPS(fec_suspend, fec_resume) + SET_RUNTIME_PM_OPS(fec_runtime_suspend, fec_runtime_resume, NULL) +}; static struct platform_driver fec_driver = { .driver = {
--
2.1.4