From: Grygorii Strashko <grygorii.strashko@ti.com>
To: Saravana Kannan <saravanak@google.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
Rob Herring <robh+dt@kernel.org>,
Frank Rowand <frowand.list@gmail.com>,
Geert Uytterhoeven <geert+renesas@glider.be>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Linux-OMAP <linux-omap@vger.kernel.org>,
Linux PM <linux-pm@vger.kernel.org>,
Peter Ujfalusi <peter.ujfalusi@ti.com>,
"Rafael J. Wysocki" <rjw@rjwysocki.net>,
Tomi Valkeinen <tomi.valkeinen@ti.com>,
Tony Lindgren <tony@atomide.com>,
Ulf Hansson <ulf.hansson@linaro.org>,
Android Kernel Team <kernel-team@android.com>,
"open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS"
<devicetree@vger.kernel.org>, LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v1] of: platform: Batch fwnode parsing in the init_machine() path
Date: Fri, 2 Oct 2020 21:11:21 +0300 [thread overview]
Message-ID: <65bfd5be-8a10-4575-41a5-94e2f4ca2729@ti.com> (raw)
In-Reply-To: <CAGETcx-wkZZQyfnkc59e2ECg_kho-O_c2ms4OOtM4=-Hd125+Q@mail.gmail.com>
On 02/10/2020 20:48, Saravana Kannan wrote:
> On Fri, Oct 2, 2020 at 8:03 AM 'Grygorii Strashko' via kernel-team
> <kernel-team@android.com> wrote:
>>
>>
>>
>> On 02/10/2020 14:40, Grygorii Strashko wrote:
>>>
>>>
>>> On 02/10/2020 02:19, Laurent Pinchart wrote:
>>>> Hi Saravana,
>>>>
>>>> Thank you for the patch.
>>>>
>>>> On Thu, Oct 01, 2020 at 03:59:51PM -0700, Saravana Kannan wrote:
>>>>> When commit 93d2e4322aa7 ("of: platform: Batch fwnode parsing when
>>>>> adding all top level devices") optimized the fwnode parsing when all top
>>>>> level devices are added, it missed out optimizing this for platform
>>>>> where the top level devices are added through the init_machine() path.
>>>>>
>>>>> This commit does the optimization for all paths by simply moving the
>>>>> fw_devlink_pause/resume() inside of_platform_default_populate().
>>>>
>>>> Based on v5.9-rc5, before the patch:
>>>>
>>>> [ 0.652887] cpuidle: using governor menu
>>>> [ 12.349476] No ATAGs?
>>>>
>>>> After the patch:
>>>>
>>>> [ 0.650460] cpuidle: using governor menu
>>>> [ 12.262101] No ATAGs?
>>>>
>>>> :-(
>>>
>>> This is kinda expected :( because omap2 arch doesn't call of_platform_default_populate()
>>>
>>> Call path:
>>> board-generic.c
>>> DT_MACHINE_START()
>>> .init_machine = omap_generic_init,
>>>
>>> omap_generic_init()
>>> pdata_quirks_init(omap_dt_match_table);
>>> of_platform_populate(NULL, omap_dt_match_table,
>>> omap_auxdata_lookup, NULL);
>>>
>>> Other affected platforms
>>> arm: mach-ux500
>>> some mips
>>> some powerpc
>>>
>>> there are also case when a lot of devices placed under bus node, in such case
>>> of_platform_populate() calls from bus drivers will also suffer from this issue.
>>>
>>> I think one option could be to add some parameter to _populate() or introduce new api.
>>>
>>> By the way, is there option to disable this feature at all?
>>> Is there Kconfig option?
>>> Is there any reasons why such complex and time consuming code added to the kernel and not implemented on DTC level?
>>>
>>>
>>> Also, I've came with another diff, pls check.
>>>
>>> [ 0.000000] Booting Linux on physical CPU 0x0
>>> [ 0.000000] Linux version 5.9.0-rc6-01791-g9acba6b38757-dirty (grygorii@grygorii-XPS-13-9370) (arm-linux-gnueabihf-gcc (GNU Toolcha0
>>> [ 0.000000] CPU: ARMv7 Processor [412fc0f2] revision 2 (ARMv7), cr=10c5387d
>>> [ 0.000000] CPU: div instructions available: patching division code
>>> [ 0.000000] CPU: PIPT / VIPT nonaliasing data cache, PIPT instruction cache
>>> [ 0.000000] OF: fdt: Machine model: TI AM5718 IDK
>>> ...
>>> [ 0.053443] cpuidle: using governor ladder
>>> [ 0.053470] cpuidle: using governor menu
>>> [ 0.089304] No ATAGs?
>>> ...
>>> [ 3.092291] devtmpfs: mounted
>>> [ 3.095804] Freeing unused kernel memory: 1024K
>>> [ 3.100483] Run /sbin/init as init process
>>>
>>>
>>>
>>> ------ >< ---
>>> diff --git a/drivers/of/platform.c b/drivers/of/platform.c
>>> index 071f04da32c8..4521b26e7745 100644
>>> --- a/drivers/of/platform.c
>>> +++ b/drivers/of/platform.c
>>> @@ -514,6 +514,12 @@ static const struct of_device_id reserved_mem_matches[] = {
>>> {}
>>> };
>>>
>>> +static int __init of_platform_fw_devlink_pause(void)
>>> +{
>>> + fw_devlink_pause();
>>> +}
>>> +core_initcall(of_platform_fw_devlink_pause);
>>> +
>>> static int __init of_platform_default_populate_init(void)
>>> {
>>> struct device_node *node;
>>> @@ -538,9 +544,7 @@ static int __init of_platform_default_populate_init(void)
>>> }
>>>
>>> /* Populate everything else. */
>>> - fw_devlink_pause();
>>> of_platform_default_populate(NULL, NULL, NULL);
>>> - fw_devlink_resume();
>>>
>>> return 0;
>>> }
>>> @@ -548,6 +552,7 @@ arch_initcall_sync(of_platform_default_populate_init);
>>>
>>> static int __init of_platform_sync_state_init(void)
>>> {
>>> + fw_devlink_resume();
>>
>> ^ it seems has to be done earlier, like
>> +static int __init of_platform_fw_devlink_resume(void)
>> +{
>> + fw_devlink_resume();
>> + return 0;
>> +}
>> +device_initcall_sync(of_platform_fw_devlink_resume);
>
> This will mean no device will probe until device_initcall_sync().
> Unfortunately, I don't think we can make such a sweeping assumption.
Could you answer below questions, pls?
>>> By the way, is there option to disable this feature at all?
>>> Is there Kconfig option?
--
Best regards,
grygorii
next prev parent reply other threads:[~2020-10-02 18:11 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-18 15:25 Slow booting on x15 Tomi Valkeinen
2020-09-18 15:58 ` Laurent Pinchart
2020-09-23 7:07 ` Tony Lindgren
2020-09-23 11:13 ` Laurent Pinchart
2020-09-24 5:42 ` Tony Lindgren
2020-09-24 5:53 ` Tony Lindgren
2020-09-24 6:04 ` Tomi Valkeinen
2020-09-24 6:08 ` Tony Lindgren
2020-09-24 13:30 ` Laurent Pinchart
2020-09-25 11:51 ` Tony Lindgren
2020-09-25 11:58 ` Laurent Pinchart
2020-09-30 5:20 ` Tony Lindgren
2020-09-30 12:41 ` Peter Ujfalusi
2020-10-01 7:53 ` Tony Lindgren
2020-10-01 8:17 ` Tony Lindgren
2020-10-01 8:22 ` Laurent Pinchart
2020-10-01 12:56 ` Grygorii Strashko
2020-10-01 13:11 ` Geert Uytterhoeven
2020-10-01 13:49 ` Grygorii Strashko
2020-10-01 18:24 ` Saravana Kannan
2020-10-01 19:43 ` Grygorii Strashko
2020-10-01 22:22 ` Saravana Kannan
2020-10-01 22:30 ` Saravana Kannan
2020-10-01 22:38 ` Laurent Pinchart
2020-10-01 22:44 ` Saravana Kannan
2020-10-01 22:59 ` [PATCH v1] of: platform: Batch fwnode parsing in the init_machine() path Saravana Kannan
2020-10-01 23:19 ` Laurent Pinchart
2020-10-02 11:40 ` Grygorii Strashko
2020-10-02 15:03 ` Grygorii Strashko
2020-10-02 17:48 ` Saravana Kannan
2020-10-02 18:11 ` Grygorii Strashko [this message]
2020-10-02 14:07 ` Rob Herring
2020-10-02 17:51 ` Saravana Kannan
2020-10-02 17:54 ` Laurent Pinchart
2020-10-02 17:58 ` Saravana Kannan
2020-10-02 18:27 ` Laurent Pinchart
2020-10-02 18:35 ` Grygorii Strashko
2020-10-02 19:56 ` Saravana Kannan
2020-10-03 0:13 ` Laurent Pinchart
2020-10-27 3:29 ` Saravana Kannan
2020-10-28 7:34 ` Tomi Valkeinen
2020-10-02 20:29 ` Rob Herring
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=65bfd5be-8a10-4575-41a5-94e2f4ca2729@ti.com \
--to=grygorii.strashko@ti.com \
--cc=devicetree@vger.kernel.org \
--cc=frowand.list@gmail.com \
--cc=geert+renesas@glider.be \
--cc=gregkh@linuxfoundation.org \
--cc=kernel-team@android.com \
--cc=laurent.pinchart@ideasonboard.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-omap@vger.kernel.org \
--cc=linux-pm@vger.kernel.org \
--cc=peter.ujfalusi@ti.com \
--cc=rjw@rjwysocki.net \
--cc=robh+dt@kernel.org \
--cc=saravanak@google.com \
--cc=tomi.valkeinen@ti.com \
--cc=tony@atomide.com \
--cc=ulf.hansson@linaro.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).