Messages in this thread | | | From | Bartosz Golaszewski <> | Date | Tue, 15 May 2018 16:06:15 +0200 | Subject | Re: [PATCH 10/12] platform/early: implement support for early platform drivers |
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2018-05-14 15:37 GMT+02:00 Rob Herring <robh+dt@kernel.org>: > On Fri, May 11, 2018 at 11:20 AM, Bartosz Golaszewski <brgl@bgdev.pl> wrote: >> From: Bartosz Golaszewski <bgolaszewski@baylibre.com> >> >> This introduces the core part of support for early platform drivers >> and devices. >> > > It looks like most of your prep patches are to separate the alloc and > init of platform devices because you are essentially making early > devices/drivers a sub-class. Maybe you could avoid doing that and > simplify things a bit. Comments below based on doing that... >
My aim was to change as little as possible for everybody else while fixing our problem. These changes are already controversial enough without risky reusing of existing fields in common structures. I was just afraid that there are too many intricacies for it to be safe.
>> +/** >> + * struct early_platform_driver >> + * >> + * @pdrv: real platform driver associated with this early platform driver >> + * @list: list head for the list of early platform drivers >> + * @early_probe: early probe callback >> + */ >> +struct early_platform_driver { >> + struct platform_driver pdrv; >> + struct list_head list; > > Couldn't you use an existing list in driver_private until you move > over to the normal bus infra. >
This is something that the previous implementation did. It was quite unreadable, so I decided to go with a separate list.
>> + int (*early_probe)(struct platform_device *); > > Just add this to platform_driver. >
This would extend the structure for everybody else while there'll be very few such devices and not all systems would even require it.
>> +}; >> + >> +/** >> + * struct early_platform_device >> + * >> + * @pdev: real platform device associated with this early platform device >> + * @list: list head for the list of early platform devices >> + * @deferred: true if this device's early probe was deferred >> + * @deferred_drv: early platform driver with which this device was matched >> + */ >> +struct early_platform_device { >> + struct platform_device pdev; >> + struct list_head list; > > Use a list in device_private? > >> + bool deferred; >> + struct early_platform_driver *deferred_drv; > > Can't you use the existing deferred probe list? >
I thought about it, but I was afraid there could be some timing issues with that and decided against it. The early deferral also doesn't work in a workque, but is synchronous instead.
Best regards, Bartosz Golaszewski
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