Re: [PATCH v1] dd: Invoke one probe retry cycle after some initcall levels
From: Rafael J. Wysocki
Date: Sun Aug 12 2018 - 04:26:31 EST
On Fri, Aug 10, 2018 at 11:52 PM Rishabh Bhatnagar
<rishabhb@xxxxxxxxxxxxxx> 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 after subsys initcall, allowing
> these drivers to be probed earlier.
>
> Signed-off-by: Vikram Mulukutla <markivx@xxxxxxxxxxxxxx>
> Signed-off-by: Rishabh Bhatnagar <rishabhb@xxxxxxxxxxxxxx>
> ---
>
> To give an example many Qualcomm drivers are dependent on the regulator and
> bus driver. Both the regulator and bus driver are probed in the
> subsys_initcall level. Now the probe of bus driver requires regulator to be
> working. If the probe of bus driver happens before regulator, then bus
> driver's probe will be deferred and all other device's probes which depend
> on bus driver will also be deferred.
> The impact of this problem is reduced if we have this patch.
Please move the above to the changelog proper (ie. above the tags) and
resend the patch with CCs to linux-pm@xxxxxxxxxxxxxxx and LKML.
Thanks,
Rafael