From mboxrd@z Thu Jan  1 00:00:00 1970
From: s-anna@ti.com (Suman Anna)
Date: Fri, 23 Dec 2016 17:57:57 -0600
Subject: [PATCH 1/2] soc: ti: Use remoteproc auto_boot feature
In-Reply-To: <1f847af8-6bde-4645-aea4-7e9b02306e39@ti.com>
References: <1481846632-4778-1-git-send-email-spjoshi@codeaurora.org>
 <1f5b2631-f744-a5c1-55c1-82eb27d5cbd7@ti.com>
 <9092e066-b2ad-ee42-de5f-d66b84a10cfd@codeaurora.org>
 <1f847af8-6bde-4645-aea4-7e9b02306e39@ti.com>
Message-ID: <6a5a9c8a-cca7-0740-4879-dd6c01e60548@ti.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On 12/23/2016 11:05 AM, Suman Anna wrote:
> Hi Sarang,
> 
>>>
>>> On 12/15/2016 06:03 PM, Sarangdhar Joshi wrote:
>>>> The function wkup_m3_rproc_boot_thread waits for asynchronous
>>>> firmware loading to complete successfully before calling
>>>> rproc_boot(). The same can be achieved by just setting
>>>> rproc->auto_boot flag. Change this. As a result this change
>>>> removes wkup_m3_rproc_boot_thread and moves m3_ipc->sync_complete
>>>> initialization to the wkup_m3_ipc_probe().
>>>>
>>>> Other than the current usage, the firmware_loading_complete is
>>>> only used in rproc_del() where it's no longer needed.  This
>>>> change is in preparation for removing firmware_loading_complete
>>>> completely.
>>>
>>> Based on the comments so far, I am assuming that you are dropping this
>>> series.
>>
>> No, may not be dropping this. Will try to handle it differently in
>> rproc_del() (probably by making use of some state flag).
>>>
>>> In any case, this series did break our PM stack. We definitely don't
>>> want to auto-boot the wkup_m3_rproc device, that responsibility will
>>> need to stay with the wkup_m3_ipc driver.
>>
>> Which scenario did it break? Booting up rproc device before
>> wkup_m3_ipc_probe() causes issues?
> 
> Yes, our state machine requires the wkup_m3_ipc driver to control the
> boot of the wkup_m3 remoteproc. The wkup_m3 is not a typical remoteproc,
> it is our PM master and is responsible for putting the host processor
> into suspend and waking it up in system suspend/cpuidle paths.
> The remoteproc infrastructure is only used for load/boot, but the Linux
> PM state machine and communication is all controlled by the wkup_m3_ipc
> driver.
> 
>>
>> Nevertheless, I think Bjorn's suggestion of just dropping the call to
>> wait_for_completion() and keeping kthread looks good, also because of
>> the fact that rproc_boot() anyways calls request_firmware() and no
>> longer needed to wait on asynchronous loading of firmware.
> 
> Yeah, I will have to test this, but looking at current code, this should
> mostly be ok because of the remoteproc core changes w.r.t resource table
> parsing.

Tested with just the wait_for_completion() removed and it works fine. I
can send a patch for the same if you prefer me to send it.

regards
Suman

> 
> regards
> Suman
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