diff options
author | Dmitry Osipenko <digetx@gmail.com> | 2020-02-25 01:40:49 +0300 |
---|---|---|
committer | Thierry Reding <treding@nvidia.com> | 2020-03-13 11:23:09 +0100 |
commit | 51da5f1cd83444024db3f1d96eccf269e25a46bc (patch) | |
tree | 9ceb8aa51c5828f65b10422eb1b50b94318abe4b | |
parent | 7ed50dd5dd12c2e69a591b2dc4d242b0e6c32dd3 (diff) | |
download | linux-51da5f1cd83444024db3f1d96eccf269e25a46bc.tar.bz2 |
ARM: tegra: cpuidle: Handle case where secondary CPU hangs on entering LP2
It is possible that something may go wrong with the secondary CPU, in
that case it is much nicer to get a dump of the flow-controller state
before hanging machine.
Acked-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Tested-by: Peter Geis <pgwipeout@gmail.com>
Tested-by: Jasper Korten <jja2000@gmail.com>
Tested-by: David Heidelberg <david@ixit.cz>
Tested-by: Nicolas Chauvet <kwizart@gmail.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
-rw-r--r-- | arch/arm/mach-tegra/cpuidle-tegra20.c | 51 |
1 files changed, 49 insertions, 2 deletions
diff --git a/arch/arm/mach-tegra/cpuidle-tegra20.c b/arch/arm/mach-tegra/cpuidle-tegra20.c index 3b61dd97bf3b..d6b9b4cf2635 100644 --- a/arch/arm/mach-tegra/cpuidle-tegra20.c +++ b/arch/arm/mach-tegra/cpuidle-tegra20.c @@ -14,6 +14,7 @@ #include <linux/tick.h> #include <linux/cpuidle.h> #include <linux/cpu_pm.h> +#include <linux/delay.h> #include <linux/kernel.h> #include <linux/module.h> @@ -82,14 +83,60 @@ static inline void tegra20_wake_cpu1_from_reset(void) } #endif +static void tegra20_report_cpus_state(void) +{ + unsigned long cpu, lcpu, csr; + + for_each_cpu(lcpu, cpu_possible_mask) { + cpu = cpu_logical_map(lcpu); + csr = flowctrl_read_cpu_csr(cpu); + + pr_err("cpu%lu: online=%d flowctrl_csr=0x%08lx\n", + cpu, cpu_online(lcpu), csr); + } +} + +static int tegra20_wait_for_secondary_cpu_parking(void) +{ + unsigned int retries = 3; + + while (retries--) { + unsigned int delay_us = 10; + unsigned int timeout_us = 500 * 1000 / delay_us; + + /* + * The primary CPU0 core shall wait for the secondaries + * shutdown in order to power-off CPU's cluster safely. + * The timeout value depends on the current CPU frequency, + * it takes about 40-150us in average and over 1000us in + * a worst case scenario. + */ + do { + if (tegra_cpu_rail_off_ready()) + return 0; + + udelay(delay_us); + + } while (timeout_us--); + + pr_err("secondary CPU taking too long to park\n"); + + tegra20_report_cpus_state(); + } + + pr_err("timed out waiting secondaries to park\n"); + + return -ETIMEDOUT; +} + static bool tegra20_cpu_cluster_power_down(struct cpuidle_device *dev, struct cpuidle_driver *drv, int index) { bool ret; - while (!tegra_cpu_rail_off_ready()) - cpu_relax(); + if (tegra20_wait_for_secondary_cpu_parking()) + return false; ret = !tegra_pm_enter_lp2(); |