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Message-ID: <20160830205939.GF3645@katana>
Date: Tue, 30 Aug 2016 22:59:40 +0200
From: Wolfram Sang <wsa@...-dreams.de>
To: Zhuo-hao Lee <zhuo-hao.lee@...el.com>
Cc: jarkko.nikula@...ux.intel.com, andriy.shevchenko@...ux.intel.com,
mika.westerberg@...ux.intel.com, linux-i2c@...r.kernel.org,
linux-kernel@...r.kernel.org
Subject: Re: [PATCH v1] i2c: designware: save the preset value of
DW_IC_SDA_HOLD
On Sat, Aug 27, 2016 at 03:39:30PM +0800, Zhuo-hao Lee wrote:
> There are several ways to set the SDA hold time for i2c controller,
> including: Device Tree, built-in device properties and ACPI. However,
> if the SDA hold time is not specified by above method, we should
> read the value, where it is preset by firmware, and save it to
> sda_hold_time. This is needed because when i2c controller enters
> runtime suspend, the DW_IC_SDA_HOLD value will be reset to chipset
> default value. And during runtime resume, i2c_dw_init will be called
> to reconfigure i2c controller. If sda_hold_time is zero, the chipset
> default hold time will be used, that will be too short for some
> platforms. Therefore, to have a better tolerance, the DW_IC_SDA_HOLD
> value should be kept by sda_hold_time.
>
> Signed-off-by: Zhuo-hao Lee <zhuo-hao.lee@...el.com>
Looks good. But is it a bugfix? Looks more like for-next material to me,
but not sure...
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