On Thu, Jul 19, 2018 at 11:24 PM, Rishabh Bhatnagar
<risha...@codeaurora.org> wrote:
> Drivers that are registered at an initcall level may have to
> wait until late_init before the probe deferral mechanism can
> retry their probe functions. It is possible that their
> dependencies were resolved much earlier, in some cases even
> before the next initcall level. Invoke one probe retry cycle
> at every _sync initcall level, allowing these drivers to be
> probed earlier.
Can you please say something about the actual use case this is
expected to address?
> Signed-off-by: Vikram Mulukutla <mark...@codeaurora.org>
> Signed-off-by: Rishabh Bhatnagar <risha...@codeaurora.org>
> ---
> drivers/base/dd.c | 33 +++++++++++++++++++++++++++------
> 1 file changed, 27 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/base/dd.c b/drivers/base/dd.c
> index 1435d72..e6a6821 100644
> --- a/drivers/base/dd.c
> +++ b/drivers/base/dd.c
> @@ -224,23 +224,44 @@ void device_unblock_probing(void)
> driver_deferred_probe_trigger();
> }
>
> +static void enable_trigger_defer_cycle(void)
> +{
> + driver_deferred_probe_enable = true;
> + driver_deferred_probe_trigger();
> + /*
> + * Sort as many dependencies as possible before the next initcall
> + * level
> + */
> + flush_work(&deferred_probe_work);
> +}
> +
> /**
> * deferred_probe_initcall() - Enable probing of deferred devices
> *
> * We don't want to get in the way when the bulk of drivers are getting
> probed.
> * Instead, this initcall makes sure that deferred probing is delayed until
> - * late_initcall time.
> + * all the registered initcall functions at a particular level are completed.
> + * This function is invoked at every *_initcall_sync level.
> */
> static int deferred_probe_initcall(void)
> {
> - driver_deferred_probe_enable = true;
> - driver_deferred_probe_trigger();
> - /* Sort as many dependencies as possible before exiting initcalls */
> - flush_work(&deferred_probe_work);
> + enable_trigger_defer_cycle();
> + driver_deferred_probe_enable = false;
> + return 0;
> +}
> +arch_initcall_sync(deferred_probe_initcall);
> +subsys_initcall_sync(deferred_probe_initcall);
> +fs_initcall_sync(deferred_probe_initcall);
> +device_initcall_sync(deferred_probe_initcall);
> +
> +static int deferred_probe_enable_fn(void)
> +{
> + /* Enable deferred probing for all time */
> + enable_trigger_defer_cycle();
> initcalls_done = true;
> return 0;
> }
> -late_initcall(deferred_probe_initcall);
> +late_initcall(deferred_probe_enable_fn);
>
> /**
> * device_is_bound() - Check if device is bound to a driver
> --
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> a Linux Foundation Collaborative Project
