From: Kevin Hilman <khilman@deeprootsystems.com>
To: Paul Walmsley <paul@pwsan.com>
Cc: Tero Kristo <t-kristo@ti.com>,
linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
Benoit Cousson <b-cousson@ti.com>,
Venkatraman S <svenkatr@ti.com>
Subject: Re: [RFC] ARM: OMAP: hwmod: wait for sysreset complete after enabling hwmod
Date: Tue, 23 Oct 2012 07:28:12 -0700 [thread overview]
Message-ID: <87txtlb6v7.fsf@deeprootsystems.com> (raw)
In-Reply-To: <alpine.DEB.2.00.1210230745160.32436@utopia.booyaka.com> (Paul Walmsley's message of "Tue, 23 Oct 2012 07:47:44 +0000 (UTC)")
Paul Walmsley <paul@pwsan.com> writes:
> Hi Tero,
>
> On Mon, 22 Oct 2012, Tero Kristo wrote:
>
>> When waking up from off-mode, some IP blocks are reset automatically by
>> hardware. For this reason, software must wait until the reset has
>> completed before attempting to access the IP block.
>>
>> This patch fixes for example the bug introduced by commit
>> 6c31b2150ff96755d24e0ab6d6fea08a7bf5c44c ("mmc: omap_hsmmc: remove access
>> to SYSCONFIG register"), in which the MMC IP block is reset during
>> off-mode entry, but the code expects the module to be already available
>> during the execution of context restore.
>>
>> Signed-off-by: Tero Kristo <t-kristo@ti.com>
>> Cc: Paul Walmsley <paul@pwsan.com>
>> Cc: Benoit Cousson <b-cousson@ti.com>
>> Cc: Venkatraman S <svenkatr@ti.com>
>
> What do you think about these modifications? The code is quite similar to
> what was in the _ocp_softreset() function, so just moved it into a
> function. Also moved the callsite from the end of _enable_sysc() to the
> beginning, which makes more sense to me, but would like to get your
> opinion.
FYI, after some more testing with this patch, I noticed that this patch
(and the original from Tero) cause some sluggishness on UART1 console my
37xx/EVM platform as soon as off-mode is enabled (even without the UART
autosuspend timeouts enabled.) I don't see this on any other OMAP3
platform but all the others I have have UART3 console (in PER), the EVM
is the only one with UART1 console (in CORE.)
I haven't debugged this any furhter, but thought it should be reported
before this gets merged.
Kevin
WARNING: multiple messages have this Message-ID (diff)
From: khilman@deeprootsystems.com (Kevin Hilman)
To: linux-arm-kernel@lists.infradead.org
Subject: [RFC] ARM: OMAP: hwmod: wait for sysreset complete after enabling hwmod
Date: Tue, 23 Oct 2012 07:28:12 -0700 [thread overview]
Message-ID: <87txtlb6v7.fsf@deeprootsystems.com> (raw)
In-Reply-To: <alpine.DEB.2.00.1210230745160.32436@utopia.booyaka.com> (Paul Walmsley's message of "Tue, 23 Oct 2012 07:47:44 +0000 (UTC)")
Paul Walmsley <paul@pwsan.com> writes:
> Hi Tero,
>
> On Mon, 22 Oct 2012, Tero Kristo wrote:
>
>> When waking up from off-mode, some IP blocks are reset automatically by
>> hardware. For this reason, software must wait until the reset has
>> completed before attempting to access the IP block.
>>
>> This patch fixes for example the bug introduced by commit
>> 6c31b2150ff96755d24e0ab6d6fea08a7bf5c44c ("mmc: omap_hsmmc: remove access
>> to SYSCONFIG register"), in which the MMC IP block is reset during
>> off-mode entry, but the code expects the module to be already available
>> during the execution of context restore.
>>
>> Signed-off-by: Tero Kristo <t-kristo@ti.com>
>> Cc: Paul Walmsley <paul@pwsan.com>
>> Cc: Benoit Cousson <b-cousson@ti.com>
>> Cc: Venkatraman S <svenkatr@ti.com>
>
> What do you think about these modifications? The code is quite similar to
> what was in the _ocp_softreset() function, so just moved it into a
> function. Also moved the callsite from the end of _enable_sysc() to the
> beginning, which makes more sense to me, but would like to get your
> opinion.
FYI, after some more testing with this patch, I noticed that this patch
(and the original from Tero) cause some sluggishness on UART1 console my
37xx/EVM platform as soon as off-mode is enabled (even without the UART
autosuspend timeouts enabled.) I don't see this on any other OMAP3
platform but all the others I have have UART3 console (in PER), the EVM
is the only one with UART1 console (in CORE.)
I haven't debugged this any furhter, but thought it should be reported
before this gets merged.
Kevin
next prev parent reply other threads:[~2012-10-23 14:27 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-22 16:15 [RFC] ARM: OMAP: hwmod: wait for sysreset complete after enabling hwmod Tero Kristo
2012-10-22 16:15 ` Tero Kristo
2012-10-22 21:46 ` Kevin Hilman
2012-10-22 21:46 ` Kevin Hilman
2012-10-23 15:43 ` Shubhrajyoti Datta
2012-10-23 15:43 ` Shubhrajyoti Datta
2012-10-23 16:09 ` Kevin Hilman
2012-10-23 16:09 ` Kevin Hilman
2012-10-23 17:50 ` Shubhrajyoti Datta
2012-10-23 17:50 ` Shubhrajyoti Datta
2012-10-23 7:47 ` Paul Walmsley
2012-10-23 7:47 ` Paul Walmsley
2012-10-23 8:03 ` Tero Kristo
2012-10-23 8:03 ` Tero Kristo
2012-10-30 3:11 ` Paul Walmsley
2012-10-30 3:11 ` Paul Walmsley
2012-10-23 14:28 ` Kevin Hilman [this message]
2012-10-23 14:28 ` Kevin Hilman
2012-10-23 14:49 ` Santosh Shilimkar
2012-10-23 14:49 ` Santosh Shilimkar
2012-10-23 17:03 ` Kevin Hilman
2012-10-23 17:03 ` Kevin Hilman
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=87txtlb6v7.fsf@deeprootsystems.com \
--to=khilman@deeprootsystems.com \
--cc=b-cousson@ti.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-omap@vger.kernel.org \
--cc=paul@pwsan.com \
--cc=svenkatr@ti.com \
--cc=t-kristo@ti.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.