From 4df27c91893fd13eaa30e9b0bca74f317816f428 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Thu, 15 Sep 2016 17:38:38 +0200 Subject: PM / OPP: avoid maybe-uninitialized warning When CONFIG_OPTIMIZE_INLINING is set and we are building with -Wmaybe-uninitialized enabled, we can get a warning for the opp core driver: drivers/base/power/opp/core.c: In function 'dev_pm_opp_set_rate': drivers/base/power/opp/core.c:560:8: warning: 'ou_volt_min' may be used uninitialized in this function [-Wmaybe-uninitialized] This has only now appeared as a result of commit 797da5598f3a ("PM / devfreq: Add COMPILE_TEST for build coverage"), which makes the driver visible in some configurations that didn't have it before. The warning is a false positive that I got with gcc-6.1.1, but there is a simple workaround in removing the local variables that we get warnings for (all three are affected depending on the configuration). This also makes the code easier to read. Signed-off-by: Arnd Bergmann Reviewed-by: Stephen Boyd Acked-by: Viresh Kumar Signed-off-by: Rafael J. Wysocki --- drivers/base/power/opp/core.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-) (limited to 'drivers/base') diff --git a/drivers/base/power/opp/core.c b/drivers/base/power/opp/core.c index df0c70963d9e..4c7c6da7a989 100644 --- a/drivers/base/power/opp/core.c +++ b/drivers/base/power/opp/core.c @@ -584,7 +584,6 @@ int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq) struct clk *clk; unsigned long freq, old_freq; unsigned long u_volt, u_volt_min, u_volt_max; - unsigned long ou_volt, ou_volt_min, ou_volt_max; int ret; if (unlikely(!target_freq)) { @@ -620,11 +619,7 @@ int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq) } old_opp = _find_freq_ceil(opp_table, &old_freq); - if (!IS_ERR(old_opp)) { - ou_volt = old_opp->u_volt; - ou_volt_min = old_opp->u_volt_min; - ou_volt_max = old_opp->u_volt_max; - } else { + if (IS_ERR(old_opp)) { dev_err(dev, "%s: failed to find current OPP for freq %lu (%ld)\n", __func__, old_freq, PTR_ERR(old_opp)); } @@ -683,7 +678,8 @@ restore_freq: restore_voltage: /* This shouldn't harm even if the voltages weren't updated earlier */ if (!IS_ERR(old_opp)) - _set_opp_voltage(dev, reg, ou_volt, ou_volt_min, ou_volt_max); + _set_opp_voltage(dev, reg, old_opp->u_volt, + old_opp->u_volt_min, old_opp->u_volt_max); return ret; } -- cgit v1.2.3 From a4ee4545932d4b26ec0c190f2ce265de79990c7a Mon Sep 17 00:00:00 2001 From: Dave Gerlach Date: Fri, 23 Sep 2016 15:07:47 -0500 Subject: PM / OPP: Don't support OPP if it provides supported-hw but platform does not The OPP framework allows each OPP to set a opp-supported-hw property which provides values that are matched against supported_hw values provided by the platform to limit support for certain OPPs on specific hardware. Currently, if the platform does not set supported_hw values, all OPPs are interpreted as supported, even if they have provided their own opp-supported-hw values. If an OPP has provided opp-supported-hw, it is indicating that there is some specific hardware configuration it is supported by. These constraints should be honored, and if no supported_hw has been provided by the platform, there is no way to determine if that OPP is actually supported, so it should be marked as not supported. Signed-off-by: Dave Gerlach Acked-by: Viresh Kumar Signed-off-by: Rafael J. Wysocki --- drivers/base/power/opp/of.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) (limited to 'drivers/base') diff --git a/drivers/base/power/opp/of.c b/drivers/base/power/opp/of.c index 1dfd3dd92624..5552211e6fcd 100644 --- a/drivers/base/power/opp/of.c +++ b/drivers/base/power/opp/of.c @@ -71,8 +71,18 @@ static bool _opp_is_supported(struct device *dev, struct opp_table *opp_table, u32 version; int ret; - if (!opp_table->supported_hw) - return true; + if (!opp_table->supported_hw) { + /* + * In the case that no supported_hw has been set by the + * platform but there is an opp-supported-hw value set for + * an OPP then the OPP should not be enabled as there is + * no way to see if the hardware supports it. + */ + if (of_find_property(np, "opp-supported-hw", NULL)) + return false; + else + return true; + } while (count--) { ret = of_property_read_u32_index(np, "opp-supported-hw", count, -- cgit v1.2.3