Re: [PATCH] i2c: tegra: Restore pinmux on system resume

[Wolfram Sang <wsa@the-dreams.de>]

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On Fri, Dec 13, 2019 at 02:44:17PM +0100, Thierry Reding wrote:
> From: Thierry Reding <treding@nvidia.com>
> 
> Depending on the board design, the I2C controllers found on Tegra SoCs
> may require pinmuxing in order to function. This is done as part of the
> driver's runtime suspend/resume operations. However, the PM core does
> not allow devices to go into runtime suspend during system sleep to
> avoid potential races with the suspend/resume of their parents.
> 
> As a result of this, when Tegra SoCs resume from system suspend, their
> I2C controllers may have lost the pinmux state in hardware, whereas the
> pinctrl subsystem is not aware of this. To fix this, make sure that if
> the I2C controller is not runtime suspended, the runtime suspend code is
> still executed in order to disable the module clock (which we don't need
> to be enabled during sleep) and set the pinmux to the idle state.
> 
> Conversely, make sure that the I2C controller is properly resumed when
> waking up from sleep so that pinmux settings are properly restored.
> 
> This fixes a bug seen with DDC transactions to an HDMI monitor timing
> out when resuming from system suspend.
> 
> Signed-off-by: Thierry Reding <treding@nvidia.com>

Do we still need this after I applied "[PATCH v5 0/8] NVIDIA Tegra I2C
driver fixes and improvements" ?


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