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Commit be92b3b5 authored by Geert Uytterhoeven's avatar Geert Uytterhoeven Committed by Greg Kroah-Hartman
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Revert "ravb: Fixed to be able to unload modules" 



commit 77972b55fb9d35d4a6b0abca99abffaa4ec6a85b upstream.

This reverts commit 1838d6c62f57836639bd3d83e7855e0ee4f6defc.

This commit moved the ravb_mdio_init() call (and thus the
of_mdiobus_register() call) from the ravb_probe() to the ravb_open()
call.  This causes a regression during system resume (s2idle/s2ram), as
new PHY devices cannot be bound while suspended.

During boot, the Micrel PHY is detected like this:

    Micrel KSZ9031 Gigabit PHY e6800000.ethernet-ffffffff:00: attached PHY driver [Micrel KSZ9031 Gigabit PHY] (mii_bus:phy_addr=e6800000.ethernet-ffffffff:00, irq=228)
    ravb e6800000.ethernet eth0: Link is Up - 1Gbps/Full - flow control off

During system suspend, (A) defer_all_probes is set to true, and (B)
usermodehelper_disabled is set to UMH_DISABLED, to avoid drivers being
probed while suspended.

  A. If CONFIG_MODULES=n, phy_device_register() calling device_add()
     merely adds the device, but does not probe it yet, as
     really_probe() returns early due to defer_all_probes being set:

       dpm_resume+0x128/0x4f8
	 device_resume+0xcc/0x1b0
	   dpm_run_callback+0x74/0x340
	     ravb_resume+0x190/0x1b8
	       ravb_open+0x84/0x770
		 of_mdiobus_register+0x1e0/0x468
		   of_mdiobus_register_phy+0x1b8/0x250
		     of_mdiobus_phy_device_register+0x178/0x1e8
		       phy_device_register+0x114/0x1b8
			 device_add+0x3d4/0x798
			   bus_probe_device+0x98/0xa0
			     device_initial_probe+0x10/0x18
			       __device_attach+0xe4/0x140
				 bus_for_each_drv+0x64/0xc8
				   __device_attach_driver+0xb8/0xe0
				     driver_probe_device.part.11+0xc4/0xd8
				       really_probe+0x32c/0x3b8

     Later, phy_attach_direct() notices no PHY driver has been bound,
     and falls back to the Generic PHY, leading to degraded operation:

       Generic PHY e6800000.ethernet-ffffffff:00: attached PHY driver [Generic PHY] (mii_bus:phy_addr=e6800000.ethernet-ffffffff:00, irq=POLL)
       ravb e6800000.ethernet eth0: Link is Up - 1Gbps/Full - flow control off

  B. If CONFIG_MODULES=y, request_module() returns early with -EBUSY due
     to UMH_DISABLED, and MDIO initialization fails completely:

       mdio_bus e6800000.ethernet-ffffffff:00: error -16 loading PHY driver module for ID 0x00221622
       ravb e6800000.ethernet eth0: failed to initialize MDIO
       PM: dpm_run_callback(): ravb_resume+0x0/0x1b8 returns -16
       PM: Device e6800000.ethernet failed to resume: error -16

     Ignoring -EBUSY in phy_request_driver_module(), like was done for
     -ENOENT in commit 21e194425abd65b5 ("net: phy: fix issue with loading
     PHY driver w/o initramfs"), would makes it fall back to the Generic
     PHY, like in the CONFIG_MODULES=n case.

Signed-off-by: default avatarGeert Uytterhoeven <geert+renesas@glider.be>
Cc: stable@vger.kernel.org
Reviewed-by: default avatarSergei Shtylyov <sergei.shtylyov@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 43198a5b

drivers/net/ethernet/renesas/ravb_main.c

+55 −55
Original line number Diff line number Diff line
@@ -1337,51 +1337,6 @@ static inline int ravb_hook_irq(unsigned int irq, irq_handler_t handler, 
	return error;

}



/* MDIO bus init function */

static int ravb_mdio_init(struct ravb_private *priv)

{

	struct platform_device *pdev = priv->pdev;

	struct device *dev = &pdev->dev;

	int error;



	/* Bitbang init */

	priv->mdiobb.ops = &bb_ops;



	/* MII controller setting */

	priv->mii_bus = alloc_mdio_bitbang(&priv->mdiobb);

	if (!priv->mii_bus)

		return -ENOMEM;



	/* Hook up MII support for ethtool */

	priv->mii_bus->name = "ravb_mii";

	priv->mii_bus->parent = dev;

	snprintf(priv->mii_bus->id, MII_BUS_ID_SIZE, "%s-%x",

		 pdev->name, pdev->id);



	/* Register MDIO bus */

	error = of_mdiobus_register(priv->mii_bus, dev->of_node);

	if (error)

		goto out_free_bus;



	return 0;



out_free_bus:

	free_mdio_bitbang(priv->mii_bus);

	return error;

}



/* MDIO bus release function */

static int ravb_mdio_release(struct ravb_private *priv)

{

	/* Unregister mdio bus */

	mdiobus_unregister(priv->mii_bus);



	/* Free bitbang info */

	free_mdio_bitbang(priv->mii_bus);



	return 0;

}



/* Network device open function for Ethernet AVB */

static int ravb_open(struct net_device *ndev)

{
@@ -1390,13 +1345,6 @@ static int ravb_open(struct net_device *ndev) 
	struct device *dev = &pdev->dev;

	int error;



	/* MDIO bus init */

	error = ravb_mdio_init(priv);

	if (error) {

		netdev_err(ndev, "failed to initialize MDIO\n");

		return error;

	}



	napi_enable(&priv->napi[RAVB_BE]);

	napi_enable(&priv->napi[RAVB_NC]);
@@ -1474,7 +1422,6 @@ static int ravb_open(struct net_device *ndev) 
out_napi_off:

	napi_disable(&priv->napi[RAVB_NC]);

	napi_disable(&priv->napi[RAVB_BE]);

	ravb_mdio_release(priv);

	return error;

}
@@ -1774,8 +1721,6 @@ static int ravb_close(struct net_device *ndev) 
	ravb_ring_free(ndev, RAVB_BE);

	ravb_ring_free(ndev, RAVB_NC);



	ravb_mdio_release(priv);



	return 0;

}
@@ -1922,6 +1867,51 @@ static const struct net_device_ops ravb_netdev_ops = { 
	.ndo_set_features	= ravb_set_features,

};



/* MDIO bus init function */

static int ravb_mdio_init(struct ravb_private *priv)

{

	struct platform_device *pdev = priv->pdev;

	struct device *dev = &pdev->dev;

	int error;



	/* Bitbang init */

	priv->mdiobb.ops = &bb_ops;



	/* MII controller setting */

	priv->mii_bus = alloc_mdio_bitbang(&priv->mdiobb);

	if (!priv->mii_bus)

		return -ENOMEM;



	/* Hook up MII support for ethtool */

	priv->mii_bus->name = "ravb_mii";

	priv->mii_bus->parent = dev;

	snprintf(priv->mii_bus->id, MII_BUS_ID_SIZE, "%s-%x",

		 pdev->name, pdev->id);



	/* Register MDIO bus */

	error = of_mdiobus_register(priv->mii_bus, dev->of_node);

	if (error)

		goto out_free_bus;



	return 0;



out_free_bus:

	free_mdio_bitbang(priv->mii_bus);

	return error;

}



/* MDIO bus release function */

static int ravb_mdio_release(struct ravb_private *priv)

{

	/* Unregister mdio bus */

	mdiobus_unregister(priv->mii_bus);



	/* Free bitbang info */

	free_mdio_bitbang(priv->mii_bus);



	return 0;

}



static const struct of_device_id ravb_match_table[] = {

	{ .compatible = "renesas,etheravb-r8a7790", .data = (void *)RCAR_GEN2 },

	{ .compatible = "renesas,etheravb-r8a7794", .data = (void *)RCAR_GEN2 },
@@ -2148,6 +2138,13 @@ static int ravb_probe(struct platform_device *pdev) 
		eth_hw_addr_random(ndev);

	}



	/* MDIO bus init */

	error = ravb_mdio_init(priv);

	if (error) {

		dev_err(&pdev->dev, "failed to initialize MDIO\n");

		goto out_dma_free;

	}



	netif_napi_add(ndev, &priv->napi[RAVB_BE], ravb_poll, 64);

	netif_napi_add(ndev, &priv->napi[RAVB_NC], ravb_poll, 64);
@@ -2169,6 +2166,8 @@ static int ravb_probe(struct platform_device *pdev) 
out_napi_del:

	netif_napi_del(&priv->napi[RAVB_NC]);

	netif_napi_del(&priv->napi[RAVB_BE]);

	ravb_mdio_release(priv);

out_dma_free:

	dma_free_coherent(ndev->dev.parent, priv->desc_bat_size, priv->desc_bat,

			  priv->desc_bat_dma);
@@ -2200,6 +2199,7 @@ static int ravb_remove(struct platform_device *pdev) 
	unregister_netdev(ndev);

	netif_napi_del(&priv->napi[RAVB_NC]);

	netif_napi_del(&priv->napi[RAVB_BE]);

	ravb_mdio_release(priv);

	pm_runtime_disable(&pdev->dev);

	free_netdev(ndev);

	platform_set_drvdata(pdev, NULL);