These two patches fix an issue observed on MT8195-Tomato where if the
mediatek-cpufreq-hw driver enabled the hardware (by writing to
REG_FREQ_ENABLE) before the SPMI controller driver (spmi-mtk-pmif),
behind which lies the big CPU supply, probed the platform would hang
shortly after with "rcu: INFO: rcu_preempt detected stalls on
CPUs/tasks" being printed in the log.
Changes in v2:
- Moved supply phandles to CPU nodes in DT
- Added fixes tags
- Added patch to verify CPU supplies are available before proceeding in
the mediatek-cpufreq-hw driver
Nícolas F. R. A. Prado (2):
arm64: dts: mediatek: cherry: Describe CPU supplies
cpufreq: mediatek-hw: Wait for CPU supplies before probing
.../boot/dts/mediatek/mt8195-cherry.dtsi | 32 +++++++++++++++++++
drivers/cpufreq/mediatek-cpufreq-hw.c | 19 ++++++++++-
2 files changed, 50 insertions(+), 1 deletion(-)
--
2.43.0
Describe in each CPU node the regulator supplying it.
Fixes: 260c04d425eb ("arm64: dts: mediatek: cherry: Enable MT6315 regulators on SPMI bus")
Signed-off-by: Nícolas F. R. A. Prado <[email protected]>
---
Changes in v2:
- Moved supplies to CPU nodes
- Added fixes tag
.../boot/dts/mediatek/mt8195-cherry.dtsi | 32 +++++++++++++++++++
1 file changed, 32 insertions(+)
diff --git a/arch/arm64/boot/dts/mediatek/mt8195-cherry.dtsi b/arch/arm64/boot/dts/mediatek/mt8195-cherry.dtsi
index 3c6079edda19..1f3a6755f155 100644
--- a/arch/arm64/boot/dts/mediatek/mt8195-cherry.dtsi
+++ b/arch/arm64/boot/dts/mediatek/mt8195-cherry.dtsi
@@ -264,6 +264,38 @@ &auxadc {
status = "okay";
};
+&cpu0 {
+ cpu-supply = <&mt6359_vcore_buck_reg>;
+};
+
+&cpu1 {
+ cpu-supply = <&mt6359_vcore_buck_reg>;
+};
+
+&cpu2 {
+ cpu-supply = <&mt6359_vcore_buck_reg>;
+};
+
+&cpu3 {
+ cpu-supply = <&mt6359_vcore_buck_reg>;
+};
+
+&cpu4 {
+ cpu-supply = <&mt6315_6_vbuck1>;
+};
+
+&cpu5 {
+ cpu-supply = <&mt6315_6_vbuck1>;
+};
+
+&cpu6 {
+ cpu-supply = <&mt6315_6_vbuck1>;
+};
+
+&cpu7 {
+ cpu-supply = <&mt6315_6_vbuck1>;
+};
+
&dp_intf0 {
status = "okay";
--
2.43.0
Il 10/01/24 15:23, Nícolas F. R. A. Prado ha scritto:
> Describe in each CPU node the regulator supplying it.
>
> Fixes: 260c04d425eb ("arm64: dts: mediatek: cherry: Enable MT6315 regulators on SPMI bus")
> Signed-off-by: Nícolas F. R. A. Prado <[email protected]>
>
Reviewed-by: AngeloGioacchino Del Regno <[email protected]>
Before proceeding with the probe and enabling frequency scaling for the
CPUs, make sure that all supplies feeding the CPUs have probed.
This fixes an issue observed on MT8195-Tomato where if the
mediatek-cpufreq-hw driver enabled the hardware (by writing to
REG_FREQ_ENABLE) before the SPMI controller driver (spmi-mtk-pmif),
behind which lies the big CPU supply, probed the platform would hang
shortly after with "rcu: INFO: rcu_preempt detected stalls on
CPUs/tasks" being printed in the log.
Fixes: 4855e26bcf4d ("cpufreq: mediatek-hw: Add support for CPUFREQ HW")
Signed-off-by: Nícolas F. R. A. Prado <[email protected]>
---
Changes in v2:
- Added this commit
drivers/cpufreq/mediatek-cpufreq-hw.c | 19 ++++++++++++++++++-
1 file changed, 18 insertions(+), 1 deletion(-)
diff --git a/drivers/cpufreq/mediatek-cpufreq-hw.c b/drivers/cpufreq/mediatek-cpufreq-hw.c
index d46afb3c0092..a1aa9385980a 100644
--- a/drivers/cpufreq/mediatek-cpufreq-hw.c
+++ b/drivers/cpufreq/mediatek-cpufreq-hw.c
@@ -13,6 +13,7 @@
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
#include <linux/slab.h>
#define LUT_MAX_ENTRIES 32U
@@ -300,7 +301,23 @@ static struct cpufreq_driver cpufreq_mtk_hw_driver = {
static int mtk_cpufreq_hw_driver_probe(struct platform_device *pdev)
{
const void *data;
- int ret;
+ int ret, cpu;
+ struct device *cpu_dev;
+ struct regulator *cpu_reg;
+
+ /* Make sure that all CPU supplies are available before proceeding. */
+ for_each_possible_cpu(cpu) {
+ cpu_dev = get_cpu_device(cpu);
+ if (!cpu_dev)
+ return dev_err_probe(&pdev->dev, -EPROBE_DEFER,
+ "Failed to get cpu%d device\n", cpu);
+
+ cpu_reg = devm_regulator_get_optional(cpu_dev, "cpu");
+ if (IS_ERR(cpu_reg))
+ return dev_err_probe(&pdev->dev, PTR_ERR(cpu_reg),
+ "CPU%d regulator get failed\n", cpu);
+ }
+
data = of_device_get_match_data(&pdev->dev);
if (!data)
--
2.43.0
On 10/01/2024 15:23, Nícolas F. R. A. Prado wrote:
> Before proceeding with the probe and enabling frequency scaling for the
> CPUs, make sure that all supplies feeding the CPUs have probed.
>
> This fixes an issue observed on MT8195-Tomato where if the
> mediatek-cpufreq-hw driver enabled the hardware (by writing to
> REG_FREQ_ENABLE) before the SPMI controller driver (spmi-mtk-pmif),
> behind which lies the big CPU supply, probed the platform would hang
> shortly after with "rcu: INFO: rcu_preempt detected stalls on
> CPUs/tasks" being printed in the log.
>
> Fixes: 4855e26bcf4d ("cpufreq: mediatek-hw: Add support for CPUFREQ HW")
> Signed-off-by: Nícolas F. R. A. Prado <[email protected]>
Reviewed-by: Matthias Brugger <[email protected]>
>
> ---
>
> Changes in v2:
> - Added this commit
>
> drivers/cpufreq/mediatek-cpufreq-hw.c | 19 ++++++++++++++++++-
> 1 file changed, 18 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/cpufreq/mediatek-cpufreq-hw.c b/drivers/cpufreq/mediatek-cpufreq-hw.c
> index d46afb3c0092..a1aa9385980a 100644
> --- a/drivers/cpufreq/mediatek-cpufreq-hw.c
> +++ b/drivers/cpufreq/mediatek-cpufreq-hw.c
> @@ -13,6 +13,7 @@
> #include <linux/of.h>
> #include <linux/of_platform.h>
> #include <linux/platform_device.h>
> +#include <linux/regulator/consumer.h>
> #include <linux/slab.h>
>
> #define LUT_MAX_ENTRIES 32U
> @@ -300,7 +301,23 @@ static struct cpufreq_driver cpufreq_mtk_hw_driver = {
> static int mtk_cpufreq_hw_driver_probe(struct platform_device *pdev)
> {
> const void *data;
> - int ret;
> + int ret, cpu;
> + struct device *cpu_dev;
> + struct regulator *cpu_reg;
> +
> + /* Make sure that all CPU supplies are available before proceeding. */
> + for_each_possible_cpu(cpu) {
> + cpu_dev = get_cpu_device(cpu);
> + if (!cpu_dev)
> + return dev_err_probe(&pdev->dev, -EPROBE_DEFER,
> + "Failed to get cpu%d device\n", cpu);
> +
> + cpu_reg = devm_regulator_get_optional(cpu_dev, "cpu");
> + if (IS_ERR(cpu_reg))
> + return dev_err_probe(&pdev->dev, PTR_ERR(cpu_reg),
> + "CPU%d regulator get failed\n", cpu);
> + }
> +
>
> data = of_device_get_match_data(&pdev->dev);
> if (!data)
On 10-01-24, 11:23, N?colas F. R. A. Prado wrote:
> Before proceeding with the probe and enabling frequency scaling for the
> CPUs, make sure that all supplies feeding the CPUs have probed.
>
> This fixes an issue observed on MT8195-Tomato where if the
> mediatek-cpufreq-hw driver enabled the hardware (by writing to
> REG_FREQ_ENABLE) before the SPMI controller driver (spmi-mtk-pmif),
> behind which lies the big CPU supply, probed the platform would hang
> shortly after with "rcu: INFO: rcu_preempt detected stalls on
> CPUs/tasks" being printed in the log.
>
> Fixes: 4855e26bcf4d ("cpufreq: mediatek-hw: Add support for CPUFREQ HW")
> Signed-off-by: N?colas F. R. A. Prado <[email protected]>
Applied 2/2. Thanks.
--
viresh
On Wed, Jan 10, 2024 at 03:32:02PM +0100, AngeloGioacchino Del Regno wrote:
> Il 10/01/24 15:23, N?colas F. R. A. Prado ha scritto:
> > Describe in each CPU node the regulator supplying it.
> >
> > Fixes: 260c04d425eb ("arm64: dts: mediatek: cherry: Enable MT6315 regulators on SPMI bus")
> > Signed-off-by: N?colas F. R. A. Prado <[email protected]>
> >
>
> Reviewed-by: AngeloGioacchino Del Regno <[email protected]>
Hello,
looks like this patch was never picked up, while the cpufreq part has been
merged for a while, so I'm still getting the mentioned hangs on linux-next.
Could this be queued? :)
Thanks,
N?colas
Il 29/02/24 21:23, Nícolas F. R. A. Prado ha scritto:
> On Wed, Jan 10, 2024 at 03:32:02PM +0100, AngeloGioacchino Del Regno wrote:
>> Il 10/01/24 15:23, Nícolas F. R. A. Prado ha scritto:
>>> Describe in each CPU node the regulator supplying it.
>>>
>>> Fixes: 260c04d425eb ("arm64: dts: mediatek: cherry: Enable MT6315 regulators on SPMI bus")
>>> Signed-off-by: Nícolas F. R. A. Prado <[email protected]>
>>>
>>
>> Reviewed-by: AngeloGioacchino Del Regno <[email protected]>
>
> Hello,
>
> looks like this patch was never picked up, while the cpufreq part has been
> merged for a while, so I'm still getting the mentioned hangs on linux-next.
> Could this be queued? :)
>
> Thanks,
> Nícolas
Will send that on the next -fixes round.
Thanks for the reminder.
+CC Nicolas Dufresne <[email protected]>
As he told me he was experiencing the hangs fixed in this series too.
On Wed, Jan 10, 2024 at 11:23:01AM -0300, N?colas F. R. A. Prado wrote:
> Describe in each CPU node the regulator supplying it.
>
> Fixes: 260c04d425eb ("arm64: dts: mediatek: cherry: Enable MT6315 regulators on SPMI bus")
> Signed-off-by: N?colas F. R. A. Prado <[email protected]>
>
> ---
>
> Changes in v2:
> - Moved supplies to CPU nodes
> - Added fixes tag
>
> .../boot/dts/mediatek/mt8195-cherry.dtsi | 32 +++++++++++++++++++
> 1 file changed, 32 insertions(+)
>
> diff --git a/arch/arm64/boot/dts/mediatek/mt8195-cherry.dtsi b/arch/arm64/boot/dts/mediatek/mt8195-cherry.dtsi
> index 3c6079edda19..1f3a6755f155 100644
> --- a/arch/arm64/boot/dts/mediatek/mt8195-cherry.dtsi
> +++ b/arch/arm64/boot/dts/mediatek/mt8195-cherry.dtsi
> @@ -264,6 +264,38 @@ &auxadc {
> status = "okay";
> };
>
> +&cpu0 {
> + cpu-supply = <&mt6359_vcore_buck_reg>;
> +};
> +
> +&cpu1 {
> + cpu-supply = <&mt6359_vcore_buck_reg>;
> +};
> +
> +&cpu2 {
> + cpu-supply = <&mt6359_vcore_buck_reg>;
> +};
> +
> +&cpu3 {
> + cpu-supply = <&mt6359_vcore_buck_reg>;
> +};
> +
> +&cpu4 {
> + cpu-supply = <&mt6315_6_vbuck1>;
> +};
> +
> +&cpu5 {
> + cpu-supply = <&mt6315_6_vbuck1>;
> +};
> +
> +&cpu6 {
> + cpu-supply = <&mt6315_6_vbuck1>;
> +};
> +
> +&cpu7 {
> + cpu-supply = <&mt6315_6_vbuck1>;
> +};
> +
> &dp_intf0 {
> status = "okay";
>
> --
> 2.43.0
>