Re: [PATCH v4 01/18] of/platform: Add common method to populate default bus

From: Kefeng Wang
Date: Thu May 26 2016 - 03:44:53 EST




On 2016/5/25 22:46, Rob Herring wrote:
> On Thu, May 12, 2016 at 7:05 AM, Kefeng Wang <wangkefeng.wang@xxxxxxxxxx> wrote:
>> The arch code calls of_platform_populate() with default match table
>> when it want to populate default bus.
>>
>> This patch introduce a new of_platform_default_populate_init() and make it
>> arch_initcall_sync(it should be later than some iommu configration, eg,
>> of_iommu_init() and swiotlb_late_init in arm64), then we can finish above
>> job in common method.
>>
>> In order to avoid the default bus being populated twice, simply checking
>> the flag of bus node whether has be set OF_POPULATED_BUS or not.
>>
>> After that, we can safely remove the caller in arch code.
>>
>> Btw, add debug print in of_platform_populate(), and use __func__ to
>> print function's name of of_platform_bus_create().
>>
>> Cc: Rob Herring <robh+dt@xxxxxxxxxx>
>> Cc: Frank Rowand <frowand.list@xxxxxxxxx>
>> Cc: Grant Likely <grant.likely@xxxxxxxxxx>
>> Signed-off-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
>> ---
>> drivers/of/platform.c | 23 ++++++++++++++++++++++-
>> 1 file changed, 22 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/of/platform.c b/drivers/of/platform.c
>> index 8d103e4..f601b30 100644
>> --- a/drivers/of/platform.c
>> +++ b/drivers/of/platform.c
>> @@ -11,6 +11,7 @@
>> * 2 of the License, or (at your option) any later version.
>> *
>> */
>> +#include <linux/acpi.h>
>> #include <linux/errno.h>
>> #include <linux/module.h>
>> #include <linux/amba/bus.h>
>> @@ -345,6 +346,12 @@ static int of_platform_bus_create(struct device_node *bus,
>> return 0;
>> }
>>
>> + if (of_node_check_flag(bus, OF_POPULATED_BUS)) {
>> + pr_debug("%s() - skipping %s, already populated\n",
>> + __func__, bus->full_name);
>> + return 0;
>> + }
>> +
>> auxdata = of_dev_lookup(lookup, bus);
>> if (auxdata) {
>> bus_id = auxdata->name;
>> @@ -396,7 +403,7 @@ int of_platform_bus_probe(struct device_node *root,
>> if (!root)
>> return -EINVAL;
>>
>> - pr_debug("of_platform_bus_probe()\n");
>> + pr_debug("%s()\n", __func__);
>> pr_debug(" starting at: %s\n", root->full_name);
>>
>> /* Do a self check of bus type, if there's a match, create children */
>> @@ -448,6 +455,9 @@ int of_platform_populate(struct device_node *root,
>> if (!root)
>> return -EINVAL;
>>
>> + pr_debug("%s()\n", __func__);
>> + pr_debug(" starting at: %s\n", root->full_name);
>> +
>> for_each_child_of_node(root, child) {
>> rc = of_platform_bus_create(child, matches, lookup, parent, true);
>> if (rc) {
>> @@ -471,6 +481,17 @@ int of_platform_default_populate(struct device_node *root,
>> }
>> EXPORT_SYMBOL_GPL(of_platform_default_populate);
>>
>> +static int __init of_platform_default_populate_init(void)
>> +{
>> + if (of_have_populated_dt())
>> + of_platform_default_populate(NULL, NULL, NULL);
>> + else if (acpi_disabled)
>
> This ACPI dependency needs to go. The error msg is somewhat pointless
> as if both DT and ACPI are not used, the boot will be horribly broken
> and I'm not sure that you would actually see the message given you
> have no information to setup a console.

Fair enough, will update and rebase patches after 4.7-rc1.

Thanks,
Kefeng

>
> Rob
>
> .
>