| From foo@baz Wed Aug 22 09:42:09 CEST 2018 |
| From: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com> |
| Date: Wed, 4 Jul 2018 11:12:40 +0300 |
| Subject: sh_eth: fix invalid context bug while changing link options by ethtool |
| |
| From: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com> |
| |
| [ Upstream commit 5cb3f52a11e18628fc4bee76dd14b1f0b76349de ] |
| |
| The change fixes sleep in atomic context bug, which is encountered |
| every time when link settings are changed by ethtool. |
| |
| Since commit 35b5f6b1a82b ("PHYLIB: Locking fixes for PHY I/O |
| potentially sleeping") phy_start_aneg() function utilizes a mutex |
| to serialize changes to phy state, however that helper function is |
| called in atomic context under a grabbed spinlock, because |
| phy_start_aneg() is called by phy_ethtool_ksettings_set() and by |
| replaced phy_ethtool_sset() helpers from phylib. |
| |
| Now duplex mode setting is enforced in sh_eth_adjust_link() only, |
| also now RX/TX is disabled when link is put down or modifications |
| to E-MAC registers ECMR and GECMR are expected for both cases of |
| checked and ignored link status pin state from E-MAC interrupt handler. |
| |
| For reference the change is a partial rework of commit 1e1b812bbe10 |
| ("sh_eth: fix handling of no LINK signal"). |
| |
| Fixes: dc19e4e5e02f ("sh: sh_eth: Add support ethtool") |
| Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com> |
| Reviewed-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> |
| Signed-off-by: David S. Miller <davem@davemloft.net> |
| Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| drivers/net/ethernet/renesas/sh_eth.c | 49 ++++++++++------------------------ |
| 1 file changed, 15 insertions(+), 34 deletions(-) |
| |
| --- a/drivers/net/ethernet/renesas/sh_eth.c |
| +++ b/drivers/net/ethernet/renesas/sh_eth.c |
| @@ -1743,8 +1743,15 @@ static void sh_eth_adjust_link(struct ne |
| { |
| struct sh_eth_private *mdp = netdev_priv(ndev); |
| struct phy_device *phydev = ndev->phydev; |
| + unsigned long flags; |
| int new_state = 0; |
| |
| + spin_lock_irqsave(&mdp->lock, flags); |
| + |
| + /* Disable TX and RX right over here, if E-MAC change is ignored */ |
| + if (mdp->cd->no_psr || mdp->no_ether_link) |
| + sh_eth_rcv_snd_disable(ndev); |
| + |
| if (phydev->link) { |
| if (phydev->duplex != mdp->duplex) { |
| new_state = 1; |
| @@ -1763,18 +1770,21 @@ static void sh_eth_adjust_link(struct ne |
| sh_eth_modify(ndev, ECMR, ECMR_TXF, 0); |
| new_state = 1; |
| mdp->link = phydev->link; |
| - if (mdp->cd->no_psr || mdp->no_ether_link) |
| - sh_eth_rcv_snd_enable(ndev); |
| } |
| } else if (mdp->link) { |
| new_state = 1; |
| mdp->link = 0; |
| mdp->speed = 0; |
| mdp->duplex = -1; |
| - if (mdp->cd->no_psr || mdp->no_ether_link) |
| - sh_eth_rcv_snd_disable(ndev); |
| } |
| |
| + /* Enable TX and RX right over here, if E-MAC change is ignored */ |
| + if ((mdp->cd->no_psr || mdp->no_ether_link) && phydev->link) |
| + sh_eth_rcv_snd_enable(ndev); |
| + |
| + mmiowb(); |
| + spin_unlock_irqrestore(&mdp->lock, flags); |
| + |
| if (new_state && netif_msg_link(mdp)) |
| phy_print_status(phydev); |
| } |
| @@ -1856,39 +1866,10 @@ static int sh_eth_get_link_ksettings(str |
| static int sh_eth_set_link_ksettings(struct net_device *ndev, |
| const struct ethtool_link_ksettings *cmd) |
| { |
| - struct sh_eth_private *mdp = netdev_priv(ndev); |
| - unsigned long flags; |
| - int ret; |
| - |
| if (!ndev->phydev) |
| return -ENODEV; |
| |
| - spin_lock_irqsave(&mdp->lock, flags); |
| - |
| - /* disable tx and rx */ |
| - sh_eth_rcv_snd_disable(ndev); |
| - |
| - ret = phy_ethtool_ksettings_set(ndev->phydev, cmd); |
| - if (ret) |
| - goto error_exit; |
| - |
| - if (cmd->base.duplex == DUPLEX_FULL) |
| - mdp->duplex = 1; |
| - else |
| - mdp->duplex = 0; |
| - |
| - if (mdp->cd->set_duplex) |
| - mdp->cd->set_duplex(ndev); |
| - |
| -error_exit: |
| - mdelay(1); |
| - |
| - /* enable tx and rx */ |
| - sh_eth_rcv_snd_enable(ndev); |
| - |
| - spin_unlock_irqrestore(&mdp->lock, flags); |
| - |
| - return ret; |
| + return phy_ethtool_ksettings_set(ndev->phydev, cmd); |
| } |
| |
| /* If it is ever necessary to increase SH_ETH_REG_DUMP_MAX_REGS, the |