Re: [PATCH v6 6/6] PCI: uniphier: Add error message when failed to get phy

From: Kunihiko Hayashi
Date: Mon Sep 07 2020 - 12:10:07 EST


Hi Rob,

On 2020/09/04 7:25, Rob Herring wrote:
On Fri, Aug 21, 2020 at 1:05 AM Kunihiko Hayashi
<hayashi.kunihiko@xxxxxxxxxxxxx> wrote:

On 2020/08/18 1:39, Rob Herring wrote:
On Fri, Aug 7, 2020 at 4:25 AM Kunihiko Hayashi
<hayashi.kunihiko@xxxxxxxxxxxxx> wrote:

Even if phy driver doesn't probe, the error message can't be distinguished
from other errors. This displays error message caused by the phy driver
explicitly.

Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@xxxxxxxxxxxxx>
---
drivers/pci/controller/dwc/pcie-uniphier.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-uniphier.c b/drivers/pci/controller/dwc/pcie-uniphier.c
index 93ef608..7c8721e 100644
--- a/drivers/pci/controller/dwc/pcie-uniphier.c
+++ b/drivers/pci/controller/dwc/pcie-uniphier.c
@@ -489,8 +489,12 @@ static int uniphier_pcie_probe(struct platform_device *pdev)
return PTR_ERR(priv->rst);

priv->phy = devm_phy_optional_get(dev, "pcie-phy");

The point of the optional variant vs. devm_phy_get() is whether or not
you get an error message. So shouldn't you switch to devm_phy_get
instead?

- if (IS_ERR(priv->phy))
- return PTR_ERR(priv->phy);
+ if (IS_ERR(priv->phy)) {
+ ret = PTR_ERR(priv->phy);
+ if (ret != -EPROBE_DEFER)
+ dev_err(dev, "Failed to get phy (%d)\n", ret);
+ return ret;
+ }

The 'phys' property is optional, so if there isn't 'phys' in the PCIe node,
devm_phy_get() returns -ENODEV, and devm_phy_optional_get() returns NULL.

When devm_phy_optional_get() replaces devm_phy_get(),
condition for displaying an error message changes to:

(ret != -EPROBE_DEFER && ret != -ENODEV)

This won't be simple, but should it be replaced?

Nevermind. I was thinking we had some error prints for the optional
vs. non-optional variants.
I understand.
As long as this phy is "optional", this doesn't need to print error message.
Once I cancel this patch, and leave the phy as "optional".

Thank you,

---
Best Regards
Kunihiko Hayashi