From: sylvain.rochet@finsecur•com (Sylvain Rochet)
To: linux-arm-kernel@lists•infradead.org
Subject: AT91 slow clock mode regression/fixes, improvement proposal
Date: Fri, 19 Dec 2014 16:26:25 +0100 [thread overview]
Message-ID: <20141219152625.GA30666@gradator.net> (raw)
In-Reply-To: <B256D81BAE5131468A838E5D7A243641BFCB6762@penmbx01>
Hello Wenyou,
On Fri, Dec 19, 2014 at 02:50:04AM +0000, Yang, Wenyou wrote:
> >
> > Is actually jumping to wait_pllblock before enabling PLLB instead of skipping UTMI
> > PLL. Unfortunately the compiler does not warn about that.
>
> Thanks. I will check it
Fixed in proposed patch (UPLL code removed).
> > Furthermore, it looks like MCKRDY_TIMEOUT set to 1000 is not enough, my board
> > crashes in about 1 wake up to 10 with this value and works perfectly
> > fine with 4000.
>
> I also encountered this issue.
Fixed in proposed patch, since we don't timeout anymore.
> Moreover the Main Crystal Oscillator Startup Time seems not enough
> too, not sure, I am confirming it.
This is OK for me, CKGR_MOR.MOSCXTST is set to 8: (1/32768)*8*8 = 1.95 ms
I checked with a scope on XTAL of the AT91SAM9G35-CM module, 2 ms is
about twice enough waiting time.
> > Therefore I am also proposing to remove all the timeout.
>
> Good idea, but I still worry the deadlock without timeout. Maybe
> increasing timeout is better.
This is just a test request patch, I am first trying without timeout to
get some feedback. It works well for me, at least, but this isn't
convicing myself enough :-)
> > By the way, I don't know for other AT91 boards (or without DT, or
> > something else), but the UTMI PLL suspend/resume seem unnecessary for
> > me, the USB driver is already disabling the USB PLL when suspending,
> > could you confirm ?
> Yes, I agree.
Removed.
> Remove disabling the PLLB code as well.
Done, but my SoC don't have a PLLB, so I can't check myself, could you
check if "AT91: PM - Suspend-to-RAM with PLL B running" does not fire on
PLL B enabled board ?
Regards,
Sylvain
next prev parent reply other threads:[~2014-12-19 15:26 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-12-18 20:39 AT91 slow clock mode regression/fixes, improvement proposal Sylvain Rochet
2014-12-18 21:23 ` Sylvain Rochet
2014-12-19 2:50 ` Yang, Wenyou
2014-12-19 15:04 ` [PATCH] pm: at91: pm_slowclock: improve reliability of suspend/resume Sylvain Rochet
2014-12-19 15:26 ` Sylvain Rochet [this message]
2014-12-22 8:32 ` AT91 slow clock mode regression/fixes, improvement proposal Yang, Wenyou
2014-12-22 10:03 ` Sylvain Rochet
2015-01-05 3:32 ` Yang, Wenyou
2015-01-06 14:15 ` [PATCH] pm: at91: pm_slowclock: improve reliability of suspend/resume Sylvain Rochet
2015-01-06 14:16 ` Sylvain Rochet
2015-01-06 14:25 ` AT91 slow clock mode regression/fixes, improvement proposal Sylvain Rochet
2015-01-07 1:17 ` Yang, Wenyou
2015-01-07 9:14 ` Alexandre Belloni
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=20141219152625.GA30666@gradator.net \
--to=sylvain.rochet@finsecur$(echo .)com \
--cc=linux-arm-kernel@lists$(echo .)infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
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