4.4-stable review patch. If anyone has any objections, please let me know.
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From: Florian Fainelli f.fainelli@gmail.com
[ Upstream commit 45ec318578c0c22a11f5b9927d064418e1ab1905 ]
The AON_PM_L2 is normally used to trigger and identify the source of a wake-up event. Since the RX_SYS clock is no longer turned off, we also have an interrupt being sent to the SYSTEMPORT INTRL_2_0 controller, and that interrupt remains active up until the magic packet detector is disabled which happens much later during the driver resumption.
The race happens if we have a CPU that is entering the SYSTEMPORT INTRL2_0 handler during resume, and another CPU has managed to clear the wake-up interrupt during bcm_sysport_resume_from_wol(). In that case, we have the first CPU stuck in the interrupt handler with an interrupt cause that has been cleared under its feet, and so we keep returning IRQ_NONE and we never make any progress.
This was not a problem before because we would always turn off the RX_SYS clock during WoL, so the SYSTEMPORT INTRL2_0 would also be turned off as well, thus not latching the interrupt.
The fix is to make sure we do not enable either the MPD or BRCM_TAG_MATCH interrupts since those are redundant with what the AON_PM_L2 interrupt controller already processes and they would cause such a race to occur.
Fixes: bb9051a2b230 ("net: systemport: Add support for WAKE_FILTER") Fixes: 83e82f4c706b ("net: systemport: add Wake-on-LAN support") Signed-off-by: Florian Fainelli f.fainelli@gmail.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/ethernet/broadcom/bcmsysport.c | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-)
--- a/drivers/net/ethernet/broadcom/bcmsysport.c +++ b/drivers/net/ethernet/broadcom/bcmsysport.c @@ -850,14 +850,22 @@ static void bcm_sysport_resume_from_wol( { u32 reg;
- /* Stop monitoring MPD interrupt */ - intrl2_0_mask_set(priv, INTRL2_0_MPD); - /* Clear the MagicPacket detection logic */ reg = umac_readl(priv, UMAC_MPD_CTRL); reg &= ~MPD_EN; umac_writel(priv, reg, UMAC_MPD_CTRL);
+ reg = intrl2_0_readl(priv, INTRL2_CPU_STATUS); + if (reg & INTRL2_0_MPD) + netdev_info(priv->netdev, "Wake-on-LAN (MPD) interrupt!\n"); + + if (reg & INTRL2_0_BRCM_MATCH_TAG) { + reg = rxchk_readl(priv, RXCHK_BRCM_TAG_MATCH_STATUS) & + RXCHK_BRCM_TAG_MATCH_MASK; + netdev_info(priv->netdev, + "Wake-on-LAN (filters 0x%02x) interrupt!\n", reg); + } + netif_dbg(priv, wol, priv->netdev, "resumed from WOL\n"); }
@@ -890,11 +898,6 @@ static irqreturn_t bcm_sysport_rx_isr(in if (priv->irq0_stat & INTRL2_0_TX_RING_FULL) bcm_sysport_tx_reclaim_all(priv);
- if (priv->irq0_stat & INTRL2_0_MPD) { - netdev_info(priv->netdev, "Wake-on-LAN interrupt!\n"); - bcm_sysport_resume_from_wol(priv); - } - return IRQ_HANDLED; }
@@ -1915,9 +1918,6 @@ static int bcm_sysport_suspend_to_wol(st /* UniMAC receive needs to be turned on */ umac_enable_set(priv, CMD_RX_EN, 1);
- /* Enable the interrupt wake-up source */ - intrl2_0_mask_clear(priv, INTRL2_0_MPD); - netif_dbg(priv, wol, ndev, "entered WOL mode\n");
return 0;