From: Wolfram Sang <wsa@the-dreams.de>
To: Xiang Wang <wangxfdu@gmail.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
Jarkko Nikula <jarkko.nikula@linux.intel.com>,
xiang.a.wang@intel.com, linux-i2c@vger.kernel.org,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 2/2] i2c: designware: enable High-speed mode for pcidrv
Date: Fri, 23 Oct 2015 22:04:07 +0200 [thread overview]
Message-ID: <20151023200407.GC1520@katana> (raw)
In-Reply-To: <CACDNBm2BkrjFHV2tcZmC+xH4kLQ724diEucRN53xEPaMrV6Jxg@mail.gmail.com>
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> > Should it (ACPI walk) be done in PCI case as well? If so, then it needs
> > to be done up to i2c-core. There you may adjust the bus speed whenever
> > slave device is enumerated.
> >
> I think the "ACPI walk for bus speed" also works for PCI case. It'll
> be good to do this in i2c-core.
> By doing this we can get a minimum device speed for this bus. I2C bus
> drivers can use this speed to set corresponding mode into i2c
> controller.
> Waiting for comments from others.
>
> > For PCI case you have still to have hardcoded values and it should be
> > maximum supported by the bus I think. When you have implemented above
> > algorithm you may do this safely. Am I missing something?
> Agree. It'll be safer to set a hardcoded maximum supported speed of
> the bus for PCI case.
> I2C bus driver can use MIN(speed_get_by_ACPI_walk,
> hardcoded_max_supported_speed) for bus speed.
Do I read this correctly that you agreed on an alternative path so this
series can be discarded?
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next prev parent reply other threads:[~2015-10-23 20:04 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-09 8:47 [PATCH 1/2] i2c: designware: add High-speed mode support wangxfdu
2015-10-09 8:47 ` [PATCH 2/2] i2c: designware: enable High-speed mode for pcidrv wangxfdu
2015-10-09 9:31 ` Andy Shevchenko
2015-10-12 7:41 ` Xiang Wang
2015-10-12 8:31 ` Andy Shevchenko
2015-10-15 5:46 ` Xiang Wang
2015-10-15 8:32 ` Jarkko Nikula
2015-10-15 9:40 ` Andy Shevchenko
2015-10-22 1:44 ` Xiang Wang
2015-10-23 20:04 ` Wolfram Sang [this message]
2015-10-09 9:29 ` [PATCH 1/2] i2c: designware: add High-speed mode support Andy Shevchenko
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