From: "Kweh, Hock Leong" <hock.leong.kweh@intel.com>
To: "David S. Miller" <davem@davemloft.net>,
Joao Pinto <Joao.Pinto@synopsys.com>,
Giuseppe CAVALLARO <peppe.cavallaro@st.com>,
seraphin.bonnaffe@st.com, f.fainelli@gmail.com
Cc: Alexandre TORGUE <alexandre.torgue@gmail.com>,
Joachim Eastwood <manabian@gmail.com>,
Niklas Cassel <niklas.cassel@axis.com>,
Johan Hovold <johan@kernel.org>,
pavel@ucw.cz, Ong Boon Leong <boon.leong.ong@intel.com>,
"Kweh, Hock Leong" <hock.leong.kweh@intel.com>,
weifeng.voon@intel.com, lars.persson@axis.com,
netdev@vger.kernel.org, LKML <linux-kernel@vger.kernel.org>
Subject: [PATCH v2] net: stmmac: bug fix to synchronize stmmac_open and stmmac_dvr_probe
Date: Tue, 27 Dec 2016 22:42:36 +0800 [thread overview]
Message-ID: <1482849756-21817-1-git-send-email-hock.leong.kweh@intel.com> (raw)
From: "Kweh, Hock Leong" <hock.leong.kweh@intel.com>
If kernel module stmmac driver being loaded after OS booted, there is a
race condition between stmmac_open() and stmmac_mdio_register(), which is
invoked inside stmmac_dvr_probe(), and the error is showed in dmesg log as
PHY not found and stmmac_open() failed:
[ 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)
The resolution moved the register_netdev() function call to the end of
stmmac_dvr_probe() after stmmac_mdio_register().
Suggested-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Kweh, Hock Leong <hock.leong.kweh@intel.com>
---
changelog v2:
* Re-implemented the fix base on David & Florian suggestion and tested.
drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 18 +++++++++---------
1 file changed, 9 insertions(+), 9 deletions(-)
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index bb40382..263ac53 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -3339,13 +3339,6 @@ int stmmac_dvr_probe(struct device *device,
spin_lock_init(&priv->lock);
- ret = register_netdev(ndev);
- if (ret) {
- netdev_err(priv->dev, "%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
@@ -3372,11 +3365,18 @@ int stmmac_dvr_probe(struct device *device,
}
}
+ ret = register_netdev(ndev);
+ if (ret) {
+ netdev_err(priv->dev, "%s: ERROR %i registering the device\n",
+ __func__, ret);
+ goto error_netdev_register;
+ }
+
return 0;
-error_mdio_register:
- unregister_netdev(ndev);
error_netdev_register:
+ stmmac_mdio_unregister(ndev);
+error_mdio_register:
netif_napi_del(&priv->napi);
error_hw_init:
clk_disable_unprepare(priv->pclk);
--
1.7.9.5
next reply other threads:[~2016-12-27 6:38 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-27 14:42 Kweh, Hock Leong [this message]
2016-12-27 10:48 ` [PATCH v2] net: stmmac: bug fix to synchronize stmmac_open and stmmac_dvr_probe Pavel Machek
2016-12-27 16:34 ` David Miller
2016-12-28 1:40 ` Kweh, Hock Leong
2016-12-28 2:23 ` [PATCH net] net: stmmac: Fix race between stmmac_drv_probe and stmmac_open Florian Fainelli
2016-12-28 2:32 ` David Miller
2016-12-28 11:56 ` [PATCH v2] net: stmmac: bug fix to synchronize stmmac_open and stmmac_dvr_probe Kishan Sandeep
2016-12-29 0:26 ` Kweh, Hock Leong
2016-12-28 5:49 ` Kweh, Hock Leong
2016-12-28 18:42 ` Florian Fainelli
2016-12-29 0:28 ` Kweh, Hock Leong
2016-12-29 0:40 ` Florian Fainelli
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