Re: [PATCH] PCI/keystone: check return value of devm_phy_get with EPROBE_DEFER

[Bjorn Helgaas]

On Fri, Mar 11, 2016 at 12:38:23PM -0600, Bjorn Helgaas wrote:
> On Mon, Mar 07, 2016 at 12:32:21PM +0800, Shawn Lin wrote:
> > If the return value of devm_phy_get is EPROBE_DEFER, we should
> > defer probing the driver.
> > 
> > Signed-off-by: Shawn Lin <shawn.lin@xxxxxxxxxxxxxx>
> 
> Applied to pci/host-keystone for v4.6 with the following changelog.
> Thanks, Shawn!
> 
>     PCI: keystone: Defer probing if devm_phy_get() returns -EPROBE_DEFER
>     
>     A SerDes PHY is optional, so if devm_phy_get() doesn't find one at all,
>     that's fine.  But if devm_phy_get() finds a PHY that doesn't have a driver
>     yet, it returns -EPROBE_DEFER.  In that case, defer probing the Keystone
>     driver.  We may be able to load it later after a PHY driver is loaded.
>     
>     [bhelgaas: changelog]
>     Signed-off-by: Shawn Lin <shawn.lin@xxxxxxxxxxxxxx>
>     Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>

I meant to include the patch, too, because I tweaked it slightly to
try to make it easier to read.  Here's what I applied:

diff --git a/drivers/pci/host/pci-keystone.c b/drivers/pci/host/pci-keystone.c
index 0aa81bd..cd70345 100644
--- a/drivers/pci/host/pci-keystone.c
+++ b/drivers/pci/host/pci-keystone.c
@@ -359,6 +359,9 @@ static int __init ks_pcie_probe(struct platform_device *pdev)
 
 	/* initialize SerDes Phy if present */
 	phy = devm_phy_get(dev, "pcie-phy");
+	if (PTR_ERR_OR_ZERO(phy) == -EPROBE_DEFER)
+		return PTR_ERR(phy);
+
 	if (!IS_ERR_OR_NULL(phy)) {
 		ret = phy_init(phy);
 		if (ret < 0)
> 
> > ---
> > 
> >  drivers/pci/host/pci-keystone.c | 2 ++
> >  1 file changed, 2 insertions(+)
> > 
> > diff --git a/drivers/pci/host/pci-keystone.c b/drivers/pci/host/pci-keystone.c
> > index 0aa81bd..42af6ac 100644
> > --- a/drivers/pci/host/pci-keystone.c
> > +++ b/drivers/pci/host/pci-keystone.c
> > @@ -363,6 +363,8 @@ static int __init ks_pcie_probe(struct platform_device *pdev)
> >  		ret = phy_init(phy);
> >  		if (ret < 0)
> >  			return ret;
> > +	} else if (PTR_ERR(phy) == -EPROBE_DEFER) {
> > +		return PTR_ERR(phy);
> >  	}
> >  
> >  	/* index 2 is to read PCI DEVICE_ID */
> > -- 
> > 2.3.7
> > 
> > 
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