linux-i2c.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Jarkko Nikula <jarkko.nikula@linux.intel.com>
To: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	chin.yew.tan@intel.com, mika.westerberg@linux.intel.com,
	wsa@the-dreams.de,
	"linux-acpi@vger.kernel.org" <linux-acpi@vger.kernel.org>,
	linux-i2c@vger.kernel.org, ken.xue@amd.com, jeff.wu@amd.com
Subject: Re: Regression: bd698d24b1b57: i2c: designware: Get selected speed mode sda-hold-time via ACPI
Date: Fri, 19 May 2017 10:11:29 +0300	[thread overview]
Message-ID: <2b97458f-245c-b914-bdff-8805b5b7ccbb@linux.intel.com> (raw)
In-Reply-To: <CAKv+Gu-=4YXovPTjWWOkN4BTFQt9qYyU781s1Qwx1vvrAMZsyQ@mail.gmail.com>

On 05/18/2017 04:44 PM, Ard Biesheuvel wrote:
> On 18 May 2017 at 14:05, Jarkko Nikula <jarkko.nikula@linux.intel.com> wrote:
>> I have a fix for this. Could you try does it fix the issue for you?
>>
>> http://www.spinics.net/lists/linux-i2c/msg29509.html
>>
>
> Thanks. But the question is really whether we want to change the
> driver so that the DW_IC_SS_SCL_HCNT/DW_IC_SS_SCL_LCNT registers are
> no longer programmed at all when running at a higher speed. Can you
> guarantee that this will not cause any change in behavior in all
> instances of this hardware that are supported currently, no matter how
> they are synthesized and described to the OS? The previous commit only
> affected the platdrv variety AFAIR
>
Obviously I cannot guarantee are there any side effects as I don't know 
the IP. However I forgot one important point: high-speed transfers 
always starts in fast-mode so those timing parameters too are needed 
when bus is configured for high-speed. So best is to write all of them.

-- 
Jarkko

      reply	other threads:[~2017-05-19  7:11 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-05-09 14:07 Regression: bd698d24b1b57: i2c: designware: Get selected speed mode sda-hold-time via ACPI Lorenzo Pieralisi
2017-05-09 14:54 ` Andy Shevchenko
2017-05-09 15:52   ` Lorenzo Pieralisi
2017-05-09 16:20     ` Andy Shevchenko
2017-05-10  9:24       ` Lorenzo Pieralisi
2017-05-10 13:55         ` Jarkko Nikula
2017-05-18 12:24           ` Ard Biesheuvel
2017-05-18 13:05             ` Jarkko Nikula
2017-05-18 13:44               ` Ard Biesheuvel
2017-05-19  7:11                 ` Jarkko Nikula [this message]

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=2b97458f-245c-b914-bdff-8805b5b7ccbb@linux.intel.com \
    --to=jarkko.nikula@linux.intel.com \
    --cc=andriy.shevchenko@linux.intel.com \
    --cc=ard.biesheuvel@linaro.org \
    --cc=chin.yew.tan@intel.com \
    --cc=jeff.wu@amd.com \
    --cc=ken.xue@amd.com \
    --cc=linux-acpi@vger.kernel.org \
    --cc=linux-i2c@vger.kernel.org \
    --cc=lorenzo.pieralisi@arm.com \
    --cc=mika.westerberg@linux.intel.com \
    --cc=wsa@the-dreams.de \
    /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).