Re: [PATCH v3 10/15] phy: tegra: xusb: Add wake/sleepwalk for Tegra210

JC Kuo
2020-10-14T08:38:09Z

On 9/28/20 9:40 PM, Thierry Reding wrote:
> On Wed, Sep 09, 2020 at 04:10:36PM +0800, JC Kuo wrote:
> [...]
>> diff --git a/drivers/phy/tegra/xusb-tegra210.c b/drivers/phy/tegra/xusb-tegra210.c
> [...]
>
> Could we add function pointers to struct tegra_xusb_lane_ops for all of
> these? That would allow us to assign them once during probe and then we
> don't have to bother with these is_*() functions and multiplexing but
> instead just call ->enable_phy_wake() and ->disable_phy_wake() directly.
Yes, I will implement in this way. Thanks for the suggestion.

>
>> +
>> +
>
> There's an extra blank line here.
>
I will remove it. Thanks.

>> static struct tegra_xusb_pad *
>> tegra210_sata_pad_probe(struct tegra_xusb_padctl *padctl,
>> const struct tegra_xusb_pad_soc *soc,
>> @@ -2293,6 +3225,8 @@ tegra210_xusb_padctl_probe(struct device *dev,
>> const struct tegra_xusb_padctl_soc *soc)
>> {
>> struct tegra210_xusb_padctl *padctl;
>> + struct device_node *node, *np = dev->of_node;
>
> We only need dev->of_node once, so I don't think we need to store it in
> a local variable. Just make this:
>
> struct device_node *np;
>
>> + struct platform_device *pmc_dev;
>
> I'd call this pdev, which is the canonical name for variables pointing
> to a platform device.
>
>> int err;
>>
>> padctl = devm_kzalloc(dev, sizeof(*padctl), GFP_KERNEL);
>> @@ -2306,6 +3240,23 @@ tegra210_xusb_padctl_probe(struct device *dev,
>> if (err < 0)
>> return ERR_PTR(err);
>>
>> + node = of_parse_phandle(np, "nvidia,pmc", 0);
>> + if (!node) {
>
> And make this:
>
> np = of_parse_phandle(dev->of_node, "nvidia,pmc", 0);
> if (!np) {
>
>> + dev_info(dev, "nvidia,pmc property is missing\n");
>
> It might be better for this to be a warning, to make it easier to catch.
>
>> + goto no_pmc;
>> + }
>> +
>> + pmc_dev = of_find_device_by_node(node);
>> + if (!pmc_dev) {
>> + dev_info(dev, "pmc device is not available\n");
>
> Same here. Also s/pmc/PMC/ in the message
>
>> + goto no_pmc;
>
> Maybe call the label "out", "done" or something similar. "no_pmc" makes
> it sound like it's meant for error cases, which makes it confusing when
> you fallthrough for the success case as well.
>
I will amend accordingly. Thanks.

> Actually, in this case it might be easier to just return here instead of
> using a goto.
>
>> + }
>> +
>> + padctl->regmap = dev_get_regmap(&pmc_dev->dev, "usb_sleepwalk");
>> + if (!padctl->regmap)
>> + dev_info(dev, "pmc regmap is not available.\n");
>
> Do we perhaps want to defer probe here?
The return value of dev_get_regmap() doesn't tell if PMC driver is loaded.

I will add the following to for defer probe.
if (!device_is_bound(&pdev->dev))
return -EPROBE_DEFER;
>
> Thierry
>

Thanks for review.
JC