[PATCH net v3 1/2] net: bcmgenet: recover from a failed resume
From: Nicolai Buchwitz
Date: Thu Oct 22 2026 - 04:55:25 EST
A resume that fails in bcmgenet_init_dma() returns with the interface
still IFF_UP and the datapath gone. The next ifdown runs the teardown
a second time and napi_disable() waits for a NAPI_STATE_SCHED bit that
nothing will clear:
task:ip state:D
usleep_range_state+0xec/0x158
napi_disable_locked+0x254/0x318
napi_disable+0x3c/0x68
bcmgenet_netif_stop+0x1c8/0x318
bcmgenet_close+0x24/0xd0
__dev_close_many+0x18c/0x310
RTNL is held across the wait, so everything else blocks behind it.
The same resume gates the clock and detaches the device. Close releases
the clock a second time and ifup fails with -ENODEV. The hardware filters
stay armed, so the next WoL suspend wakes on any frame. That suspend sets
CMD_RX_EN for magic packet detection, so the WoL resume reuses rings that
are gone.
A failed resume should leave a state the ordinary paths can handle. Clear
rx_cbs and tx_cbs as they are freed so they answer whether a datapath
exists, and leave the clock alone so close and suspend release it once.
The WoL resume rebuilds instead, so stop the PHY first, phy_start() only
takes PHY_READY or PHY_HALTED.
Flagged in a sashiko review and reproduced on a CM4 by forcing the resume
allocation to fail.
Fixes: b6e978e50444 ("net: bcmgenet: add suspend/resume callbacks")
Fixes: 254f3239dd07 ("net: bcmgenet: revise suspend/resume") # for the WoL parts
Signed-off-by: Nicolai Buchwitz <nb@xxxxxxxxxxx>
---
drivers/net/ethernet/broadcom/genet/bcmgenet.c | 92 +++++++++++++++++---------
1 file changed, 62 insertions(+), 30 deletions(-)
diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.c b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
index f4cfbff49a1b8..e7dec73d5b1c0 100644
--- a/drivers/net/ethernet/broadcom/genet/bcmgenet.c
+++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
@@ -3117,7 +3117,9 @@ static void bcmgenet_fini_dma(struct bcmgenet_priv *priv)
bcmgenet_free_rx_buffers(priv);
bcmgenet_destroy_rx_page_pools(priv);
kfree(priv->rx_cbs);
+ priv->rx_cbs = NULL;
kfree(priv->tx_cbs);
+ priv->tx_cbs = NULL;
}
/* init_edma: Initialize DMA control register */
@@ -3175,6 +3177,7 @@ static int bcmgenet_init_dma(struct bcmgenet_priv *priv, bool flush_rx)
priv->tx_cbs = kzalloc_objs(struct enet_cb, priv->num_tx_bds);
if (!priv->tx_cbs) {
kfree(priv->rx_cbs);
+ priv->rx_cbs = NULL;
return -ENOMEM;
}
@@ -3194,7 +3197,9 @@ static int bcmgenet_init_dma(struct bcmgenet_priv *priv, bool flush_rx)
bcmgenet_free_rx_buffers(priv);
bcmgenet_destroy_rx_page_pools(priv);
kfree(priv->rx_cbs);
+ priv->rx_cbs = NULL;
kfree(priv->tx_cbs);
+ priv->tx_cbs = NULL;
return ret;
}
@@ -3503,7 +3508,9 @@ static int bcmgenet_close(struct net_device *dev)
netif_dbg(priv, ifdown, dev, "bcmgenet_close\n");
- bcmgenet_netif_stop(dev, false);
+ /* A failed resume has torn the datapath down already */
+ if (priv->tx_cbs)
+ bcmgenet_netif_stop(dev, false);
/* Really kill the PHY state machine and disconnect from it */
phy_disconnect(dev->phydev);
@@ -3511,6 +3518,9 @@ static int bcmgenet_close(struct net_device *dev)
free_irq(priv->irq0, priv);
free_irq(priv->irq1, priv);
+ /* A failed resume left the device detached, __dev_open() refuses that */
+ netif_device_attach(dev);
+
if (priv->internal_phy)
ret = bcmgenet_power_down(priv, GENET_POWER_PASSIVE);
@@ -4268,7 +4278,11 @@ static int bcmgenet_resume(struct device *d)
if (device_may_wakeup(d) && priv->wolopts) {
reg = bcmgenet_umac_readl(priv, UMAC_CMD);
- if (reg & CMD_RX_EN) {
+
+ /* The WoL power down sets CMD_RX_EN itself, so the bit
+ * alone does not mean the rings survived
+ */
+ if (priv->tx_cbs && (reg & CMD_RX_EN)) {
/* Successfully exited WoL, just resume data flows */
list_for_each_entry(rule, &priv->rxnfc_list, list)
if (rule->state == BCMGENET_RXNFC_STATE_ENABLED)
@@ -4298,6 +4312,9 @@ static int bcmgenet_resume(struct device *d)
bcmgenet_rdma_disable(priv);
bcmgenet_intr_disable(priv);
bcmgenet_fini_dma(priv);
+ if (phy_is_started(dev->phydev) ||
+ dev->phydev->state == PHY_ERROR)
+ phy_stop(dev->phydev);
enable_irq(priv->irq1);
}
@@ -4320,8 +4337,9 @@ static int bcmgenet_resume(struct device *d)
/* Reinitialize TDMA and RDMA and SW housekeeping */
ret = bcmgenet_init_dma(priv, false);
if (ret) {
+ /* Leave the block clocked, close and suspend tear it down */
netdev_err(dev, "failed to initialize DMA\n");
- goto out_clk_disable;
+ return ret;
}
if (!device_may_wakeup(d))
@@ -4332,24 +4350,57 @@ static int bcmgenet_resume(struct device *d)
netif_device_attach(dev);
return 0;
+}
-out_clk_disable:
- if (priv->internal_phy)
- bcmgenet_power_down(priv, GENET_POWER_PASSIVE);
- clk_disable_unprepare(priv->clk);
- return ret;
+/* Arm the configured wake filters and drop the rest, then clear old
+ * matches so that only a new one wakes the system
+ */
+static void bcmgenet_wol_arm_filters(struct bcmgenet_priv *priv)
+{
+ struct bcmgenet_rxnfc_rule *rule;
+ u32 reg, hfb_enable = 0;
+
+ if (priv->wolopts & WAKE_FILTER)
+ list_for_each_entry(rule, &priv->rxnfc_list, list)
+ if (rule->fs.ring_cookie == RX_CLS_FLOW_WAKE &&
+ rule->state == BCMGENET_RXNFC_STATE_ENABLED)
+ hfb_enable |= 1 << rule->fs.location;
+
+ reg = bcmgenet_hfb_reg_readl(priv, HFB_CTRL);
+ if (GENET_IS_V1(priv) || GENET_IS_V2(priv)) {
+ reg &= ~RBUF_HFB_FILTER_EN_MASK;
+ reg |= hfb_enable << (RBUF_HFB_FILTER_EN_SHIFT + 1);
+ } else {
+ bcmgenet_hfb_reg_writel(priv, hfb_enable << 1,
+ HFB_FLT_ENABLE_V3PLUS + 4);
+ }
+ if (!hfb_enable)
+ reg &= ~RBUF_HFB_EN;
+ bcmgenet_hfb_reg_writel(priv, reg, HFB_CTRL);
+
+ bcmgenet_intrl2_0_writel(priv, 0xFFFFFFFF, INTRL2_CPU_MASK_SET);
+ bcmgenet_intrl2_0_writel(priv, 0xFFFFFFFF, INTRL2_CPU_CLEAR);
}
static int bcmgenet_suspend(struct device *d)
{
struct net_device *dev = dev_get_drvdata(d);
struct bcmgenet_priv *priv = netdev_priv(dev);
- struct bcmgenet_rxnfc_rule *rule;
- u32 reg, hfb_enable = 0;
if (!netif_running(dev))
return 0;
+ /* A failed resume has torn the datapath down already. Resume still
+ * enables irq1 on the WoL path, so it has to be disabled here.
+ */
+ if (!priv->tx_cbs) {
+ if (device_may_wakeup(d) && priv->wolopts) {
+ bcmgenet_wol_arm_filters(priv);
+ disable_irq(priv->irq1);
+ }
+ return 0;
+ }
+
netif_device_detach(dev);
if (device_may_wakeup(d) && priv->wolopts) {
@@ -4358,26 +4409,7 @@ static int bcmgenet_suspend(struct device *d)
netif_tx_disable(dev);
/* Suspend non-wake Rx data flows */
- if (priv->wolopts & WAKE_FILTER)
- list_for_each_entry(rule, &priv->rxnfc_list, list)
- if (rule->fs.ring_cookie == RX_CLS_FLOW_WAKE &&
- rule->state == BCMGENET_RXNFC_STATE_ENABLED)
- hfb_enable |= 1 << rule->fs.location;
- reg = bcmgenet_hfb_reg_readl(priv, HFB_CTRL);
- if (GENET_IS_V1(priv) || GENET_IS_V2(priv)) {
- reg &= ~RBUF_HFB_FILTER_EN_MASK;
- reg |= hfb_enable << (RBUF_HFB_FILTER_EN_SHIFT + 1);
- } else {
- bcmgenet_hfb_reg_writel(priv, hfb_enable << 1,
- HFB_FLT_ENABLE_V3PLUS + 4);
- }
- if (!hfb_enable)
- reg &= ~RBUF_HFB_EN;
- bcmgenet_hfb_reg_writel(priv, reg, HFB_CTRL);
-
- /* Clear any old filter matches so only new matches wake */
- bcmgenet_intrl2_0_writel(priv, 0xFFFFFFFF, INTRL2_CPU_MASK_SET);
- bcmgenet_intrl2_0_writel(priv, 0xFFFFFFFF, INTRL2_CPU_CLEAR);
+ bcmgenet_wol_arm_filters(priv);
if (-ETIMEDOUT == bcmgenet_tdma_disable(priv))
netdev_warn(priv->dev,
--
2.53.0