linux-kernel - [PATCH] cpufreq: tegra: add regulator dependency for T124

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <2194927.eV2s2QmZs0@wuerfel>
Date:	Tue, 08 Dec 2015 22:52:45 +0100
From:	Arnd Bergmann <arnd@...db.de>
To:	linux-pm@...r.kernel.org
Cc:	"Rafael J. Wysocki" <rjw@...ysocki.net>,
	Viresh Kumar <viresh.kumar@...aro.org>,
	Stephen Warren <swarren@...dotorg.org>,
	Thierry Reding <thierry.reding@...il.com>,
	Alexandre Courbot <gnurou@...il.com>,
	linux-tegra@...r.kernel.org, linux-kernel@...r.kernel.org,
	linux-arm-kernel@...ts.infradead.org, broonie@...nel.org,
	Liam Girdwood <lgirdwood@...il.com>
Subject: [PATCH] cpufreq: tegra: add regulator dependency for T124

This driver is the only one that calls regulator_sync_voltage(), but it
can currently be built with CONFIG_REGULATOR disabled, producing
this build error:

drivers/cpufreq/tegra124-cpufreq.c: In function 'tegra124_cpu_switch_to_pllx':
drivers/cpufreq/tegra124-cpufreq.c:68:2: error: implicit declaration of function 'regulator_sync_voltage' [-Werror=implicit-function-declaration]
  regulator_sync_voltage(priv->vdd_cpu_reg);

My first attempt was to implement a helper for this function
for regulator_sync_voltage, but Mark Brown explained:

   We don't do this for *all* regulator API functions - there's some where
   using them strongly suggests that there is actually a dependency on
   the regulator API.  This does seem like it might be falling into the
   specialist category [...]
   Looking at the code I'm pretty unclear on what the authors think the
   use of _sync_voltage() is doing in the first place so it may be even
   better to just remove the call.  It seems to have been included in the
   first commit so there's not changelog explaining things and there's
   no comment either.  I'd *expect* it to be a noop as far as I can see.

This adds the dependency to make the driver always build successfully
or not be enabled at all. Alternatively, we could investigate if the
driver should stop calling regulator_sync_voltage instead.

Signed-off-by: Arnd Bergmann <arnd@...db.de>

diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm
index 235a1ba73d92..b1f8a73e5a94 100644
--- a/drivers/cpufreq/Kconfig.arm
+++ b/drivers/cpufreq/Kconfig.arm
@@ -226,7 +226,7 @@ config ARM_TEGRA20_CPUFREQ

 config ARM_TEGRA124_CPUFREQ
 	tristate "Tegra124 CPUFreq support"
-	depends on ARCH_TEGRA && CPUFREQ_DT
+	depends on ARCH_TEGRA && CPUFREQ_DT && REGULATOR
 	default y
 	help
 	  This adds the CPUFreq driver support for Tegra124 SOCs.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/