This is a note to let you know that I've just added the patch titled
net: stmmac: Fix race between stmmac_drv_probe and stmmac_open
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
net-stmmac-fix-race-between-stmmac_drv_probe-and-stmmac_open.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Thu Jan 12 21:37:26 CET 2017
From: Florian Fainelli <f.fainelli@xxxxxxxxx>
Date: Tue, 27 Dec 2016 18:23:06 -0800
Subject: net: stmmac: Fix race between stmmac_drv_probe and stmmac_open
From: Florian Fainelli <f.fainelli@xxxxxxxxx>
[ Upstream commit 5701659004d68085182d2fd4199c79172165fa65 ]
There is currently a small window during which the network device registered by
stmmac can be made visible, yet all resources, including and clock and MDIO bus
have not had a chance to be set up, this can lead to the following error to
occur:
[ 473.919358] stmmaceth 0000:01:00.0 (unnamed net_device) (uninitialized):
stmmac_dvr_probe: warning: cannot get CSR clock
[ 473.919382] stmmaceth 0000:01:00.0: no reset control found
[ 473.919412] stmmac - user ID: 0x10, Synopsys ID: 0x42
[ 473.919429] stmmaceth 0000:01:00.0: DMA HW capability register supported
[ 473.919436] stmmaceth 0000:01:00.0: RX Checksum Offload Engine supported
[ 473.919443] stmmaceth 0000:01:00.0: TX Checksum insertion supported
[ 473.919451] stmmaceth 0000:01:00.0 (unnamed net_device) (uninitialized):
Enable RX Mitigation via HW Watchdog Timer
[ 473.921395] libphy: PHY stmmac-1:00 not found
[ 473.921417] stmmaceth 0000:01:00.0 eth0: Could not attach to PHY
[ 473.921427] stmmaceth 0000:01:00.0 eth0: stmmac_open: Cannot attach to
PHY (error: -19)
[ 473.959710] libphy: stmmac: probed
[ 473.959724] stmmaceth 0000:01:00.0 eth0: PHY ID 01410cc2 at 0 IRQ POLL
(stmmac-1:00) active
[ 473.959728] stmmaceth 0000:01:00.0 eth0: PHY ID 01410cc2 at 1 IRQ POLL
(stmmac-1:01)
[ 473.959731] stmmaceth 0000:01:00.0 eth0: PHY ID 01410cc2 at 2 IRQ POLL
(stmmac-1:02)
[ 473.959734] stmmaceth 0000:01:00.0 eth0: PHY ID 01410cc2 at 3 IRQ POLL
(stmmac-1:03)
Fix this by making sure that register_netdev() is the last thing being done,
which guarantees that the clock and the MDIO bus are available.
Fixes: 4bfcbd7abce2 ("stmmac: Move the mdio_register/_unregister in probe/remove")
Reported-by: Kweh, Hock Leong <hock.leong.kweh@xxxxxxxxx>
Signed-off-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 23 ++++++++++++----------
1 file changed, 13 insertions(+), 10 deletions(-)
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -3349,12 +3349,6 @@ int stmmac_dvr_probe(struct device *devi
spin_lock_init(&priv->lock);
spin_lock_init(&priv->tx_lock);
- ret = register_netdev(ndev);
- if (ret) {
- pr_err("%s: ERROR %i registering the device\n", __func__, ret);
- goto error_netdev_register;
- }
-
/* If a specific clk_csr value is passed from the platform
* this means that the CSR Clock Range selection cannot be
* changed at run-time and it is fixed. Viceversa the driver'll try to
@@ -3376,15 +3370,24 @@ int stmmac_dvr_probe(struct device *devi
if (ret < 0) {
pr_debug("%s: MDIO bus (id: %d) registration failed",
__func__, priv->plat->bus_id);
- goto error_mdio_register;
+ goto error_napi_register;
}
}
- return 0;
+ ret = register_netdev(ndev);
+ if (ret) {
+ pr_err("%s: ERROR %i registering the device\n", __func__, ret);
+ goto error_netdev_register;
+ }
+
+ return ret;
-error_mdio_register:
- unregister_netdev(ndev);
error_netdev_register:
+ if (priv->hw->pcs != STMMAC_PCS_RGMII &&
+ priv->hw->pcs != STMMAC_PCS_TBI &&
+ priv->hw->pcs != STMMAC_PCS_RTBI)
+ stmmac_mdio_unregister(ndev);
+error_napi_register:
netif_napi_del(&priv->napi);
error_hw_init:
clk_disable_unprepare(priv->pclk);
Patches currently in stable-queue which might be from f.fainelli@xxxxxxxxx are
queue-4.9/net-dsa-ensure-validity-of-dst-ds.patch
queue-4.9/net-stmmac-fix-race-between-stmmac_drv_probe-and-stmmac_open.patch
queue-4.9/net-dsa-bcm_sf2-utilize-nested-mdio-read-write.patch
queue-4.9/net-dsa-bcm_sf2-do-not-clobber-b53_switch_ops.patch
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