linux-kernel - [PATCH v2] PM / Domains: Remove obsolete "samsung,power-domain" check

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Date:   Thu, 30 Nov 2017 12:54:28 +0100
From:   Geert Uytterhoeven <geert+renesas@...der.be>
To:     "Rafael J . Wysocki" <rjw@...ysocki.net>,
        Kevin Hilman <khilman@...nel.org>,
        Ulf Hansson <ulf.hansson@...aro.org>,
        Kukjin Kim <kgene@...nel.org>,
        Krzysztof Kozlowski <krzk@...nel.org>
Cc:     linux-pm@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        linux-samsung-soc@...r.kernel.org, linux-kernel@...r.kernel.org,
        Geert Uytterhoeven <geert+renesas@...der.be>
Subject: [PATCH v2] PM / Domains: Remove obsolete "samsung,power-domain" check

Currently the generic PM Domain code code checks for the presence of
both (generic) "power-domains" and (Samsung Exynos legacy)
"samsung,power-domain" properties in all device tree nodes representing
devices.

There are two issues with this:
  1. This imposes a small boot-time penalty on all platforms using DT,
  2. Platform-specific checks do not really belong in core framework
     code.

Remove the platform-specific check, as the last user of
"samsung,power-domain" was removed in commit 46dcf0ff0de35da8 ("ARM:
dts: exynos: Remove exynos4415.dtsi").  All other users were converted
before in commit 0da6587041363033 ("ARM: dts: convert to generic power
domain bindings for exynos DT").

Signed-off-by: Geert Uytterhoeven <geert+renesas@...der.be>
---
This is v2 of 'PM / Domains: Restrict "samsung,power-domain" checks to
ARCH_EXYNOS'.

"samsung,power-domain" was only ever used in:
  - arch/arm/boot/dts/exynos4415.dtsi: Removed
  - arch/arm/boot/dts/exynos3250.dtsi: CONFIG_ARCH_EXYNOS3
  - arch/arm/boot/dts/exynos4.dtsi:    CONFIG_ARCH_EXYNOS4
  - arch/arm/boot/dts/exynos4x12.dtsi: CONFIG_ARCH_EXYNOS4
  - arch/arm/boot/dts/exynos5250.dtsi: CONFIG_ARCH_EXYNOS5
  - arch/arm/boot/dts/exynos5420.dtsi: CONFIG_ARCH_EXYNOS5

v2:
  - Remove the check completely instead of restricting it to
    ARCH_EXYNOS, as suggested Javier Martinez Canillas one year ago
    ("Removing the support for the deprecated property sound sensible to me",
    http://lists.infradead.org/pipermail/linux-arm-kernel/2016-October/462868.html).
---
 drivers/base/power/domain.c | 16 ++--------------
 1 file changed, 2 insertions(+), 14 deletions(-)

diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index 0c80bea05bcb92be..f9dcc981b6b9328c 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -2199,20 +2199,8 @@ int genpd_dev_pm_attach(struct device *dev)
 
 	ret = of_parse_phandle_with_args(dev->of_node, "power-domains",
 					"#power-domain-cells", 0, &pd_args);
-	if (ret < 0) {
-		if (ret != -ENOENT)
-			return ret;
-
-		/*
-		 * Try legacy Samsung-specific bindings
-		 * (for backwards compatibility of DT ABI)
-		 */
-		pd_args.args_count = 0;
-		pd_args.np = of_parse_phandle(dev->of_node,
-						"samsung,power-domain", 0);
-		if (!pd_args.np)
-			return -ENOENT;
-	}
+	if (ret < 0)
+		return ret;
 
 	mutex_lock(&gpd_list_lock);
 	pd = genpd_get_from_provider(&pd_args);
-- 
2.7.4