Re: [PATCHv2 1/2] pci: spear: Use platform_driver_probe instead of platform_driver_register

Stanimir Varbanov
2015-02-11T07:53:33Z

Hi,

On 02/11/2015 05:35 AM, Viresh Kumar wrote:
> On 11 February 2015 at 00:31, Matwey V. Kornilov <matwey@sai.msu.ru> wrote:
>> Use platform_driver_probe instead of platform_driver_register
>> because the former allows us to use probe function placed into __init section
>> and the driver itself is not support hotplugging (yet?).
>>
>> Signed-off-by: Matwey V. Kornilov <matwey@sai.msu.ru>
>> ---
>> Changes from v1:
>> - Use platform_driver_probe instead of platform_driver_register to make linker happy.
>>
>> drivers/pci/host/pcie-spear13xx.c | 3 +--
>> 1 file changed, 1 insertion(+), 2 deletions(-)
>>
>> diff --git a/drivers/pci/host/pcie-spear13xx.c b/drivers/pci/host/pcie-spear13xx.c
>> index 866465f..51e1344 100644
>> --- a/drivers/pci/host/pcie-spear13xx.c
>> +++ b/drivers/pci/host/pcie-spear13xx.c
>> @@ -371,7 +371,6 @@ static const struct of_device_id spear13xx_pcie_of_match[] = {
>> MODULE_DEVICE_TABLE(of, spear13xx_pcie_of_match);
>>
>> static struct platform_driver spear13xx_pcie_driver __initdata = {
>> - .probe = spear13xx_pcie_probe,
>> .driver = {
>> .name = "spear-pcie",
>> .of_match_table = of_match_ptr(spear13xx_pcie_of_match),
>> @@ -382,7 +381,7 @@ static struct platform_driver spear13xx_pcie_driver __initdata = {
>>
>> static int __init spear13xx_pcie_init(void)
>> {
>> - return platform_driver_register(&spear13xx_pcie_driver);
>> + return platform_driver_probe(&spear13xx_pcie_driver, spear13xx_pcie_probe);
>> }
>> module_init(spear13xx_pcie_init);
>
> The problem here is that the driver is never registered. And we might never
> see it in sysfs. Probably a better solution would be to just remove all __init
> parts from this driver. Let it take space even after it is used. And don't care
> about it.
>
> Sorry was busy in a conference and couldn't reply to your earlier mail on this.

Using platform_driver_probe() prevents deferred probe which is problem
because you get phy, clocks from probe, and these calls could return
EPROBE_DEFFER.

Also dw_pcie_host_init() called from spear13xx_add_pcie_port() is
annotated as __init. I wanted send a patch which removes __init from
dw_pcie_host_init() but I haven't time, yet.

regards,
Stan