Hello Ranjani,
On Mon, Mar 2, 2020 at 11:24 PM Sridharan, Ranjani
<ranjani.sridharan@xxxxxxxxx> wrote:
>> + */
>> +struct dev_multi_pm_domain_data *dev_multi_pm_attach(struct device *dev)
>> +{
>> + struct dev_multi_pm_domain_data *mpd, *retp;
>> + int num_domains;
>> + int i;
>> +
>> + num_domains = of_count_phandle_with_args(dev->of_node, "power-domains",
>> + "#power-domain-cells");
>> + if (num_domains < 2)
>
> Hi Daniel,
>
> Just out of curiosity, should it be an error when num_domains is 1? Is it an error because the expectation is that the caller would use dev_pm_domain_attach() in that case?
NULL here doesn't really mean an error. It means that we don't need to
handle Power domains because as you said the caller
already used dev_pm_domain_attach.
Similar with this:
$ drivers/base/power/domain.c +2504
int genpd_dev_pm_attach(struct device *dev)
/ * Devices with multiple PM domains must be attached separately, as we
* can only attach one PM domain per device.
*/
if (of_count_phandle_with_args(dev->of_node, "power-domains",
"#power-domain-cells") != 1)
return 0;
Will update the description for when this function returns a NULL.
>
>> + return NULL;
>> +
>> + mpd = devm_kzalloc(dev, GFP_KERNEL, sizeof(*mpd));
>> + if (!mpd)
>> + return ERR_PTR(-ENOMEM);
>> +
>> + mpd->dev = dev;
>> + mpd->num_domains = num_domains;
>> +
>> + mpd->virt_devs = devm_kmalloc_array(dev, mpd->num_domains,
>> + sizeof(*mpd->virt_devs),
>> + GFP_KERNEL);
>> + if (!mpd->virt_devs)
>> + return ERR_PTR(-ENOMEM);
>> +
>> + mpd->links = devm_kmalloc_array(dev, mpd->num_domains,
>> + sizeof(*mpd->links), GFP_KERNEL);
>> + if (!mpd->links)
>> + return ERR_PTR(-ENOMEM);
>> +
>> + for (i = 0; i < mpd->num_domains; i++) {
>> + mpd->virt_devs[i] = dev_pm_domain_attach_by_id(dev, i);
>> + if (IS_ERR(mpd->virt_devs[i])) {
>> + retp = (struct dev_multi_pm_domain_data *)
>> + mpd->virt_devs[i];
>
> Should retp be PTR_ERR(mpd->virt_devs[i]) here?
PTR_ERR returns a long but our function needs to return struct
dev_multi_pm_domain_data *.
> Thanks,
> Ranjani
