Re: [PATCH 10/10] drivers: misc: use module_platform_driver_probe()
From: Fabio Porcedda
Date: Thu Mar 21 2013 - 09:10:45 EST
On Wed, Mar 20, 2013 at 12:46 PM, Arnd Bergmann <arnd@xxxxxxxx> wrote:
> On Wednesday 20 March 2013, Fabio Porcedda wrote:
>> On Wed, Mar 20, 2013 at 11:20 AM, Arnd Bergmann <arnd@xxxxxxxx> wrote:
>> > On Wednesday 20 March 2013, Fabio Porcedda wrote:
>> >> I think we can check inside the deferred_probe_work_func()
>> >> if the dev->probe function pointer is equal to platform_drv_probe_fail().
>> > I think it's too late by then, because that would only warn if we try to probe
>> > it again, but when platform_driver_probe() does not succeed immediately, it
>> Maybe you mean "does succeed immediately" ?
> I mean in this code (simplified for the sake of discussion)
> int __init_or_module platform_driver_probe(struct platform_driver *drv,
> int (*probe)(struct platform_device *))
> int retval, code;
> drv->probe = probe;
> retval = code = platform_driver_register(drv);
> drv->probe = NULL;
> if (code == 0 && list_empty(&drv->driver.p->klist_devices.k_list))
> retval = -ENODEV;
> drv->driver.probe = platform_drv_probe_fail;
> if (code != retval)
> return retval;
> we assume that all devices are bound to drivers during the call to
> platform_driver_register, and if the device list is empty afterwards,
> we unregister the driver and will never get to the deferred probing
Thanks for the explanation, I understand now that is not that simple.
I was hoping it was easier.
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