From: Dmitry Osipenko <digetx@gmail.com>
To: Krishna Yarlagadda <kyarlagadda@nvidia.com>,
linux-i2c@vger.kernel.org, thierry.reding@gmail.com
Cc: jonathanh@nvidia.com, linux-tegra@vger.kernel.org,
linux-kernel@vger.kernel.org, ldewangan@nvidia.com,
smohammed@nvidia.com, rgumasta@nvidia.com
Subject: Re: [PATCH 5/7] i2c: tegra: enable second level clock gating
Date: Thu, 23 Jul 2020 17:01:43 +0300 [thread overview]
Message-ID: <1f51823f-09ea-80d5-69dd-7772474a3fb1@gmail.com> (raw)
In-Reply-To: <1595506733-10307-5-git-send-email-kyarlagadda@nvidia.com>
23.07.2020 15:18, Krishna Yarlagadda пишет:
> Enable Second Level Clock Gating feature for supported chips.
> With SLCG enabled, software need not control clocks anymore
> and leave clocks enabled always on.
What problem is solved by this patch? If there is no real problem, then
I'm not sure that this is a worthwhile patch. Please explain.
...
> @@ -1932,7 +1946,8 @@ static int __maybe_unused tegra_i2c_suspend(struct device *dev)
> struct tegra_i2c_dev *i2c_dev = dev_get_drvdata(dev);
> int err = 0;
>
> - i2c_mark_adapter_suspended(&i2c_dev->adapter);
Why i2c_mark_adapter_suspended() is removed?
> + if (i2c_dev->is_clkon_always)
> + clk_disable(i2c_dev->div_clk);
Why clk needs to be disabled on suspend?
> if (!pm_runtime_status_suspended(dev))
> err = tegra_i2c_runtime_suspend(dev);
> @@ -1968,6 +1983,15 @@ static int __maybe_unused tegra_i2c_resume(struct device *dev)
> return err;
> }
>
> + if (i2c_dev->is_clkon_always) {
> + err = clk_enable(i2c_dev->div_clk);
> + if (err < 0) {
> + dev_err(i2c_dev->dev, "clock enable failed %d\n",
> + err);
> + return err;
> + }
> + }
Would be nice if it all could be wrapped into
tegra_i2c_div_clk_enable/disable() helpers.
> i2c_mark_adapter_resumed(&i2c_dev->adapter);
>
> return 0;
>
next prev parent reply other threads:[~2020-07-23 14:01 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-23 12:18 [PATCH 1/7] i2c: tegra: remove dead code Krishna Yarlagadda
2020-07-23 12:18 ` [PATCH 2/7] i2c: tegra: Fix setting of controller ID Krishna Yarlagadda
2020-07-23 12:18 ` [PATCH 4/7] i2c: tegra: add high speed mode support Krishna Yarlagadda
[not found] ` <1595506733-10307-4-git-send-email-kyarlagadda-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
2020-07-23 13:27 ` Dmitry Osipenko
2020-07-25 11:26 ` Michał Mirosław
2020-07-23 12:18 ` [PATCH 5/7] i2c: tegra: enable second level clock gating Krishna Yarlagadda
2020-07-23 14:01 ` Dmitry Osipenko [this message]
2020-07-23 12:18 ` [PATCH 6/7] i2c: tegra: DMA support for t186 and t194 Krishna Yarlagadda
[not found] ` <1595506733-10307-6-git-send-email-kyarlagadda-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
2020-07-23 13:16 ` Dmitry Osipenko
2020-07-23 13:38 ` Dmitry Osipenko
[not found] ` <1595506733-10307-1-git-send-email-kyarlagadda-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
2020-07-23 12:18 ` [PATCH 3/7] i2c: tegra: add flag for register write buffering Krishna Yarlagadda
2020-07-23 13:17 ` Dmitry Osipenko
2020-07-23 12:18 ` [PATCH 7/7] i2c: tegra: dump I2C registers on timeout Krishna Yarlagadda
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