From: Sudeep Holla <sudeep.holla@arm.com>
To: Rob Herring <robh@kernel.org>
Cc: Saravana Kannan <saravanak@google.com>,
Geert Uytterhoeven <geert+renesas@glider.be>,
Linus Walleij <linus.walleij@linaro.org>,
Russell King <linux@armlinux.org.uk>,
John Stultz <john.stultz@linaro.org>,
linux-arm-kernel@lists.infradead.org,
Sudeep Holla <sudeep.holla@arm.com>,
Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Subject: Re: [PATCH] amba: Retry adding deferred devices at late_initcall
Date: Tue, 28 Apr 2020 16:51:32 +0100 [thread overview]
Message-ID: <20200428155132.GA11891@bogus> (raw)
In-Reply-To: <20200427212514.11219-1-robh@kernel.org>
On Mon, Apr 27, 2020 at 04:25:14PM -0500, Rob Herring wrote:
> If amba bus devices defer when adding, the amba bus code simply retries
> adding the devices every 5 seconds. This doesn't work well as it
> completely unsynchronized with starting the init process which can
> happen in less than 5 secs. Add a retry during late_initcall. If the
> amba devices are added, then deferred probe takes over. If the
> dependencies have not probed at this point, then there's no improvement
> over previous behavior. To completely solve this, we'd need to retry
> after every successful probe as deferred probe does.
>
> The list_empty() check now happens outside the mutex, but the mutex
> wasn't necessary in the first place.
>
> This needed to use deferred probe instead of fragile initcall ordering
> on 32-bit VExpress systems where the apb_pclk has a number of probe
> dependencies (vexpress-sysregs, vexpress-config).
>
> Cc: John Stultz <john.stultz@linaro.org>
> Cc: Saravana Kannan <saravanak@google.com>
> Cc: Linus Walleij <linus.walleij@linaro.org>
> Cc: Sudeep Holla <sudeep.holla@arm.com>
The change makes sense to me,
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
This also fixed the issue I reported @[1] is fixed with this patch, so:
Tested-by: Sudeep Holla <sudeep.holla@arm.com>
--
Regards,
Sudeep
[1] https://lore.kernel.org/linux-arm-kernel/20200423133342.GA10628@bogus/
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2020-04-28 15:51 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-27 21:25 [PATCH] amba: Retry adding deferred devices at late_initcall Rob Herring
2020-04-28 15:51 ` Sudeep Holla [this message]
2020-04-28 20:39 ` Linus Walleij
2020-04-29 6:06 ` Marek Szyprowski
2020-04-29 7:33 ` Saravana Kannan
2020-05-04 19:10 ` Ulf Hansson
2020-05-04 19:28 ` Saravana Kannan
2020-05-07 11:44 ` Marek Szyprowski
2020-05-07 17:39 ` Saravana Kannan
2020-05-08 13:41 ` Rob Herring
2020-05-08 19:19 ` Saravana Kannan
2020-04-29 12:26 ` Linus Walleij
2020-04-29 14:01 ` 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=20200428155132.GA11891@bogus \
--to=sudeep.holla@arm.com \
--cc=geert+renesas@glider.be \
--cc=john.stultz@linaro.org \
--cc=linus.walleij@linaro.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux@armlinux.org.uk \
--cc=nsaenzjulienne@suse.de \
--cc=robh@kernel.org \
--cc=saravanak@google.com \
/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).