diff options
| author | Nícolas F. R. A. Prado <nfraprado@collabora.com> | 2024-01-10 17:23:02 +0300 |
|---|---|---|
| committer | Sasha Levin <sashal@kernel.org> | 2024-03-27 01:16:32 +0300 |
| commit | 3243524cd60502dae16b8a9b36c134c42f34dafa (patch) | |
| tree | 7e23bb854794d8676577e81c0d466f615f918dcd /drivers/cpufreq | |
| parent | e6e3e51ffba0784782b1a076d7441605697ea3c6 (diff) | |
| download | linux-3243524cd60502dae16b8a9b36c134c42f34dafa.tar.xz | |
cpufreq: mediatek-hw: Wait for CPU supplies before probing
[ Upstream commit 788715b5f21c6455264fe00a1779e61bec407fe2 ]
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 <nfraprado@collabora.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/cpufreq')
| -rw-r--r-- | drivers/cpufreq/mediatek-cpufreq-hw.c | 19 |
1 files changed, 18 insertions, 1 deletions
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) |