From: Chanwoo Choi <cw00.choi@samsung.com>
To: k.konieczny@partner.samsung.com
Cc: Mark Rutland <mark.rutland@arm.com>, Nishanth Menon <nm@ti.com>,
linux-samsung-soc@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>,
Stephen Boyd <sboyd@kernel.org>,
Viresh Kumar <vireshk@kernel.org>,
linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org,
Krzysztof Kozlowski <krzk@kernel.org>,
Rob Herring <robh+dt@kernel.org>,
Kyungmin Park <kyungmin.park@samsung.com>,
Kukjin Kim <kgene@kernel.org>,
MyungJoo Ham <myungjoo.ham@samsung.com>,
devicetree@vger.kernel.org,
Marek Szyprowski <m.szyprowski@samsung.com>
Subject: Re: [PATCH v3 1/5] devfreq: exynos-bus: correct clock enable sequence
Date: Thu, 25 Jul 2019 18:58:43 +0900 [thread overview]
Message-ID: <9c29db92-2452-0ff3-3ffa-d861e4327bc9@samsung.com> (raw)
In-Reply-To: <20190719150535.15501-2-k.konieczny@partner.samsung.com>
Hi Kamil,
On 19. 7. 20. 오전 12:05, k.konieczny@partner.samsung.com wrote:
> Regulators should be enabled before clocks to avoid h/w hang. This
> require change in exynos_bus_probe() to move exynos_bus_parse_of()
> after exynos_bus_parent_parse_of() and change in enabling sequence
> of regulator and clock in exynos_bus_parse_of(). Similar change is
> needed in exynos_bus_exit() where clock should be disabled first.
>
> Signed-off-by: Kamil Konieczny <k.konieczny@partner.samsung.com>
> ---
> This patch is new to this series.
>
> ---
> drivers/devfreq/exynos-bus.c | 58 ++++++++++++++++++++----------------
> 1 file changed, 32 insertions(+), 26 deletions(-)
>
> diff --git a/drivers/devfreq/exynos-bus.c b/drivers/devfreq/exynos-bus.c
> index 486cc5b422f1..f391044aa39d 100644
> --- a/drivers/devfreq/exynos-bus.c
> +++ b/drivers/devfreq/exynos-bus.c
> @@ -194,11 +194,11 @@ static void exynos_bus_exit(struct device *dev)
> if (ret < 0)
> dev_warn(dev, "failed to disable the devfreq-event devices\n");
>
> + clk_disable_unprepare(bus->clk);
> if (bus->regulator)
> regulator_disable(bus->regulator);
>
> dev_pm_opp_of_remove_table(dev);
> - clk_disable_unprepare(bus->clk);
> }
>
> /*
> @@ -326,8 +326,7 @@ static int exynos_bus_parent_parse_of(struct device_node *np,
> return ret;
> }
>
> -static int exynos_bus_parse_of(struct device_node *np,
> - struct exynos_bus *bus)
> +static int exynos_bus_parse_of(struct exynos_bus *bus)
> {
> struct device *dev = bus->dev;
> struct dev_pm_opp *opp;
> @@ -341,36 +340,35 @@ static int exynos_bus_parse_of(struct device_node *np,
> return PTR_ERR(bus->clk);
> }
>
> - ret = clk_prepare_enable(bus->clk);
> + /* Get the freq and voltage from OPP table to scale the bus freq */
> + ret = dev_pm_opp_of_add_table(dev);
> if (ret < 0) {
> - dev_err(dev, "failed to get enable clock\n");
> + dev_err(dev, "failed to get OPP table\n");
> return ret;
> }
>
> - /* Get the freq and voltage from OPP table to scale the bus freq */
> - ret = dev_pm_opp_of_add_table(dev);
> + ret = clk_prepare_enable(bus->clk);
> if (ret < 0) {
> - dev_err(dev, "failed to get OPP table\n");
> + dev_err(dev, "failed to enable clock\n");
> goto err_clk;
> }
> -
> rate = clk_get_rate(bus->clk);
>
> opp = devfreq_recommended_opp(dev, &rate, 0);
> if (IS_ERR(opp)) {
> dev_err(dev, "failed to find dev_pm_opp\n");
> ret = PTR_ERR(opp);
> - goto err_opp;
> + goto err;
> }
> bus->curr_freq = dev_pm_opp_get_freq(opp);
> dev_pm_opp_put(opp);
>
> return 0;
>
> -err_opp:
> - dev_pm_opp_of_remove_table(dev);
> -err_clk:
> +err:
> clk_disable_unprepare(bus->clk);
> +err_clk:
> + dev_pm_opp_of_remove_table(dev);
>
> return ret;
> }
> @@ -386,6 +384,7 @@ static int exynos_bus_probe(struct platform_device *pdev)
> struct exynos_bus *bus;
> int ret, max_state;
> unsigned long min_freq, max_freq;
> + bool passive = false;
>
> if (!np) {
> dev_err(dev, "failed to find devicetree node\n");
> @@ -399,27 +398,31 @@ static int exynos_bus_probe(struct platform_device *pdev)
> bus->dev = &pdev->dev;
> platform_set_drvdata(pdev, bus);
>
> - /* Parse the device-tree to get the resource information */
> - ret = exynos_bus_parse_of(np, bus);
> - if (ret < 0)
> - return ret;
> -
> profile = devm_kzalloc(dev, sizeof(*profile), GFP_KERNEL);
> - if (!profile) {
> - ret = -ENOMEM;
> - goto err;
> - }
> + if (!profile)
> + return -ENOMEM;
>
> node = of_parse_phandle(dev->of_node, "devfreq", 0);
> if (node) {
> of_node_put(node);
> - goto passive;
> + passive = true;
> } else {
> ret = exynos_bus_parent_parse_of(np, bus);
> + if (ret < 0)
> + return ret;
> }
>
> - if (ret < 0)
> - goto err;
> + /* Parse the device-tree to get the resource information */
> + ret = exynos_bus_parse_of(bus);
> + if (ret < 0) {
> + if (!passive)
> + regulator_disable(bus->regulator);
> +
> + return ret;
> + }
> +
> + if (passive)
> + goto passive;
>
> /* Initialize the struct profile and governor data for parent device */
> profile->polling_ms = 50;
> @@ -508,8 +511,11 @@ static int exynos_bus_probe(struct platform_device *pdev)
> return 0;
>
> err:
> - dev_pm_opp_of_remove_table(dev);
> clk_disable_unprepare(bus->clk);
> + if (!passive)
> + regulator_disable(bus->regulator);
> +
> + dev_pm_opp_of_remove_table(dev);
>
> return ret;
> }
>
Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
--
Best Regards,
Chanwoo Choi
Samsung Electronics
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next prev parent reply other threads:[~2019-07-25 9:55 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CGME20190719150553eucas1p142b965afae13224712d51f9c28162165@eucas1p1.samsung.com>
2019-07-19 15:05 ` [PATCH v3 0/5] add coupled regulators for Exynos5422/5800 k.konieczny
[not found] ` <CGME20190719150553eucas1p1665462f3fc0e06fc9c082e258be3a851@eucas1p1.samsung.com>
2019-07-19 15:05 ` [PATCH v3 1/5] devfreq: exynos-bus: correct clock enable sequence k.konieczny
2019-07-25 9:58 ` Chanwoo Choi [this message]
[not found] ` <CGME20190719150554eucas1p2f4c9e4d2767ab740d419c42d4aeed6d5@eucas1p2.samsung.com>
2019-07-19 15:05 ` [PATCH v3 2/5] opp: core: add regulators enable and disable k.konieczny
2019-07-23 1:48 ` Viresh Kumar
[not found] ` <CGME20190719150555eucas1p197adc3c58e45c53137fd70cadbfae60e@eucas1p1.samsung.com>
2019-07-19 15:05 ` [PATCH v3 3/5] devfreq: exynos-bus: convert to use dev_pm_opp_set_rate() k.konieczny
2019-07-25 10:17 ` Chanwoo Choi
2019-07-25 13:35 ` Kamil Konieczny
2019-07-25 14:53 ` Chanwoo Choi
2019-07-25 15:15 ` Kamil Konieczny
2019-07-26 1:02 ` Chanwoo Choi
[not found] ` <CGME20190719150556eucas1p291b9e533a80d77e2f58452f0e1fe8b35@eucas1p2.samsung.com>
2019-07-19 15:05 ` [PATCH v3 4/5] ARM: dts: exynos: add initial data for coupled regulators for Exynos5422/5800 k.konieczny
[not found] ` <CGME20190719150556eucas1p2bc6f133c48ec1be9b36119a414887969@eucas1p2.samsung.com>
2019-07-19 15:05 ` [PATCH v3 5/5] dt-bindings: devfreq: exynos-bus: remove unused property k.konieczny
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