6.5-stable review patch. If anyone has any objections, please let me know.
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From: Vladimir Oltean vladimir.oltean@nxp.com
[ Upstream commit 139ad1143151a07be93bf741d4ea7c89e59f89ce ]
The protocol converter configuration registers PCC8, PCCC, PCCD (implemented by the driver), as well as others, control protocol converters from multiple lanes (each represented as a different struct phy). So, if there are simultaneous calls to phy_set_mode_ext() to lanes sharing the same PCC register (either for the "old" or for the "new" protocol), corruption of the values programmed to hardware is possible, because lynx_28g_rmw() has no locking.
Add a spinlock in the struct lynx_28g_priv shared by all lanes, and take the global spinlock from the phy_ops :: set_mode() implementation. There are no other callers which modify PCC registers.
Fixes: 8f73b37cf3fb ("phy: add support for the Layerscape SerDes 28G") Signed-off-by: Vladimir Oltean vladimir.oltean@nxp.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/phy/freescale/phy-fsl-lynx-28g.c | 9 +++++++++ 1 file changed, 9 insertions(+)
diff --git a/drivers/phy/freescale/phy-fsl-lynx-28g.c b/drivers/phy/freescale/phy-fsl-lynx-28g.c index d49aa59c7d812..0a8b40edc3f31 100644 --- a/drivers/phy/freescale/phy-fsl-lynx-28g.c +++ b/drivers/phy/freescale/phy-fsl-lynx-28g.c @@ -126,6 +126,10 @@ struct lynx_28g_lane { struct lynx_28g_priv { void __iomem *base; struct device *dev; + /* Serialize concurrent access to registers shared between lanes, + * like PCCn + */ + spinlock_t pcc_lock; struct lynx_28g_pll pll[LYNX_28G_NUM_PLL]; struct lynx_28g_lane lane[LYNX_28G_NUM_LANE];
@@ -396,6 +400,8 @@ static int lynx_28g_set_mode(struct phy *phy, enum phy_mode mode, int submode) if (powered_up) lynx_28g_power_off(phy);
+ spin_lock(&priv->pcc_lock); + switch (submode) { case PHY_INTERFACE_MODE_SGMII: case PHY_INTERFACE_MODE_1000BASEX: @@ -412,6 +418,8 @@ static int lynx_28g_set_mode(struct phy *phy, enum phy_mode mode, int submode) lane->interface = submode;
out: + spin_unlock(&priv->pcc_lock); + /* Power up the lane if necessary */ if (powered_up) lynx_28g_power_on(phy); @@ -595,6 +603,7 @@ static int lynx_28g_probe(struct platform_device *pdev)
dev_set_drvdata(dev, priv);
+ spin_lock_init(&priv->pcc_lock); INIT_DELAYED_WORK(&priv->cdr_check, lynx_28g_cdr_lock_check);
queue_delayed_work(system_power_efficient_wq, &priv->cdr_check,