On 30-11-16, 15:19, Joonyoung Shim wrote:
Hi Viresh,
On 11/30/2016 12:59 PM, Viresh Kumar wrote:
From: Stephen Boyd sboyd@codeaurora.org
Joonyoung Shim reported an interesting problem on his ARM octa-core Odoroid-XU3 platform. During system suspend, dev_pm_opp_put_regulator() was failing for a struct device for which dev_pm_opp_set_regulator() is called earlier.
This happened because an earlier call to dev_pm_opp_of_cpumask_remove_table() function (from cpufreq-dt.c file) removed all the entries from opp_table->dev_list apart from the last CPU device in the cpumask of CPUs sharing the OPP.
But both dev_pm_opp_set_regulator() and dev_pm_opp_put_regulator() routines get CPU device for the first CPU in the cpumask. And so the OPP core failed to find the OPP table for the struct device.
In order to fix that up properly, we need to revisit APIs like dev_pm_opp_set_regulator() and make them talk in terms of cookies provided by the OPP core. But such a solution will be hard to backport to stable kernels.
This patch attempts to fix this problem by returning a pointer to the opp_table from dev_pm_opp_set_regulator() and using that as the parameter to dev_pm_opp_put_regulator(). This ensures that the dev_pm_opp_put_regulator() doesn't fail to find the opp table.
Note that similar design problem also exists with other dev_pm_opp_put_*() APIs, but those aren't used currently by anyone and so we don't need to update them for now.
[Viresh]: Written commit log, minor improvements in the patch and tested on exynos 5250.
Cc: # v4.4+ stable@vger.kernel.org Reported-by: Joonyoung Shim jy0922.shim@samsung.com Signed-off-by: Stephen Boyd sboyd@codeaurora.org Signed-off-by: Viresh Kumar viresh.kumar@linaro.org
V3->V4:
- Completely different approach, suggested earlier by Stephen.
- Can be merged safely now as both /me and Stephen agree to this one.
@Joonyoung: Can you please test this last patch please ?
Just system suspend/resume is working
Should I consider that as a Tested-by from you for the problem you reported at least ?
but i was missing below test case that you inform when i test for prior patches on my Odroid-XU3 board.
- offline CPU 4
- suspend the system
With this test case, now all patches posted have the problem that is failed to get clk: -2.
That probably happens because your DT isn't good enough. Following DT change may fix it for you:
diff --git a/arch/arm/boot/dts/exynos5422-cpus.dtsi b/arch/arm/boot/dts/exynos5422-cpus.dtsi index bf3c6f1ec4ee..998a7dad95fc 100644 --- a/arch/arm/boot/dts/exynos5422-cpus.dtsi +++ b/arch/arm/boot/dts/exynos5422-cpus.dtsi @@ -41,6 +41,7 @@ device_type = "cpu"; compatible = "arm,cortex-a7"; reg = <0x101>; + clocks = <&clock CLK_KFC_CLK>; clock-frequency = <1000000000>; cci-control-port = <&cci_control0>; operating-points-v2 = <&cluster_a7_opp_table>; @@ -53,6 +54,7 @@ device_type = "cpu"; compatible = "arm,cortex-a7"; reg = <0x102>; + clocks = <&clock CLK_KFC_CLK>; clock-frequency = <1000000000>; cci-control-port = <&cci_control0>; operating-points-v2 = <&cluster_a7_opp_table>; @@ -65,6 +67,7 @@ device_type = "cpu"; compatible = "arm,cortex-a7"; reg = <0x103>; + clocks = <&clock CLK_KFC_CLK>; clock-frequency = <1000000000>; cci-control-port = <&cci_control0>; operating-points-v2 = <&cluster_a7_opp_table>; @@ -89,6 +92,7 @@ cpu5: cpu@1 { device_type = "cpu"; compatible = "arm,cortex-a15"; + clocks = <&clock CLK_ARM_CLK>; reg = <0x1>; clock-frequency = <1800000000>; cci-control-port = <&cci_control1>; @@ -101,6 +105,7 @@ cpu6: cpu@2 { device_type = "cpu"; compatible = "arm,cortex-a15"; + clocks = <&clock CLK_ARM_CLK>; reg = <0x2>; clock-frequency = <1800000000>; cci-control-port = <&cci_control1>; @@ -113,6 +118,7 @@ cpu7: cpu@3 { device_type = "cpu"; compatible = "arm,cortex-a15"; + clocks = <&clock CLK_ARM_CLK>; reg = <0x3>; clock-frequency = <1800000000>; cci-control-port = <&cci_control1>;