From ffe12855a5f7f195589130197558e6a5c276caa4 Mon Sep 17 00:00:00 2001 From: Ulf Hansson Date: Mon, 30 Nov 2015 16:21:38 +0100 Subject: PM / Domains: Allow runtime PM callbacks to be re-used during system PM A runtime PM centric subsystem/driver may typically use the runtime PM helpers, pm_runtime_force_suspend|resume() in the system PM path. This means the genpd's runtime PM callbacks might be invoked even when runtime PM has been disabled for the device. To properly cope with these and similar scenarios when these helper functions are used, change genpd to skip validating and measuring the device PM QOS latency. This is needed because otherwise genpd may prevent the device to be put into low power state. If this occurs during system PM, it causes the sequence to be aborted as a device's system PM callback returns -EBUSY. Fixes: ba2bbfbf6307 (PM / Domains: Remove intermediate states from the power off sequence) Reported-by: Cao Minh Hiep Reported-by: Harunaga Signed-off-by: Ulf Hansson Cc: 4.3+ # 4.3+ Signed-off-by: Rafael J. Wysocki --- drivers/base/power/domain.c | 33 ++++++++++++++++++++++----------- 1 file changed, 22 insertions(+), 11 deletions(-) (limited to 'drivers/base') diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c index 4e3a1f108b9c..8ad59f3e6f80 100644 --- a/drivers/base/power/domain.c +++ b/drivers/base/power/domain.c @@ -390,6 +390,7 @@ static int pm_genpd_runtime_suspend(struct device *dev) struct generic_pm_domain *genpd; bool (*stop_ok)(struct device *__dev); struct gpd_timing_data *td = &dev_gpd_data(dev)->td; + bool runtime_pm = pm_runtime_enabled(dev); ktime_t time_start; s64 elapsed_ns; int ret; @@ -400,12 +401,19 @@ static int pm_genpd_runtime_suspend(struct device *dev) if (IS_ERR(genpd)) return -EINVAL; + /* + * A runtime PM centric subsystem/driver may re-use the runtime PM + * callbacks for other purposes than runtime PM. In those scenarios + * runtime PM is disabled. Under these circumstances, we shall skip + * validating/measuring the PM QoS latency. + */ stop_ok = genpd->gov ? genpd->gov->stop_ok : NULL; - if (stop_ok && !stop_ok(dev)) + if (runtime_pm && stop_ok && !stop_ok(dev)) return -EBUSY; /* Measure suspend latency. */ - time_start = ktime_get(); + if (runtime_pm) + time_start = ktime_get(); ret = genpd_save_dev(genpd, dev); if (ret) @@ -418,13 +426,15 @@ static int pm_genpd_runtime_suspend(struct device *dev) } /* Update suspend latency value if the measured time exceeds it. */ - elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start)); - if (elapsed_ns > td->suspend_latency_ns) { - td->suspend_latency_ns = elapsed_ns; - dev_dbg(dev, "suspend latency exceeded, %lld ns\n", - elapsed_ns); - genpd->max_off_time_changed = true; - td->constraint_changed = true; + if (runtime_pm) { + elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start)); + if (elapsed_ns > td->suspend_latency_ns) { + td->suspend_latency_ns = elapsed_ns; + dev_dbg(dev, "suspend latency exceeded, %lld ns\n", + elapsed_ns); + genpd->max_off_time_changed = true; + td->constraint_changed = true; + } } /* @@ -453,6 +463,7 @@ static int pm_genpd_runtime_resume(struct device *dev) { struct generic_pm_domain *genpd; struct gpd_timing_data *td = &dev_gpd_data(dev)->td; + bool runtime_pm = pm_runtime_enabled(dev); ktime_t time_start; s64 elapsed_ns; int ret; @@ -479,14 +490,14 @@ static int pm_genpd_runtime_resume(struct device *dev) out: /* Measure resume latency. */ - if (timed) + if (timed && runtime_pm) time_start = ktime_get(); genpd_start_dev(genpd, dev); genpd_restore_dev(genpd, dev); /* Update resume latency value if the measured time exceeds it. */ - if (timed) { + if (timed && runtime_pm) { elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start)); if (elapsed_ns > td->resume_latency_ns) { td->resume_latency_ns = elapsed_ns; -- cgit From 26bbe7ef6d5cdc7ec08cba6d433fca4060f258f3 Mon Sep 17 00:00:00 2001 From: Seth Jennings Date: Fri, 11 Dec 2015 13:40:57 -0800 Subject: drivers/base/memory.c: prohibit offlining of memory blocks with missing sections Commit bdee237c0343 ("x86: mm: Use 2GB memory block size on large-memory x86-64 systems") and 982792c782ef ("x86, mm: probe memory block size for generic x86 64bit") introduced large block sizes for x86. This made it possible to have multiple sections per memory block where previously, there was a only every one section per block. Since blocks consist of contiguous ranges of section, there can be holes in the blocks where sections are not present. If one attempts to offline such a block, a crash occurs since the code is not designed to deal with this. This patch is a quick fix to gaurd against the crash by not allowing blocks with non-present sections to be offlined. Addresses https://bugzilla.kernel.org/show_bug.cgi?id=107781 Signed-off-by: Seth Jennings Reported-by: Andrew Banman Cc: Daniel J Blueman Cc: Yinghai Lu Cc: Greg KH Cc: Russ Anderson Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/base/memory.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'drivers/base') diff --git a/drivers/base/memory.c b/drivers/base/memory.c index 2804aed3f416..25425d3f2575 100644 --- a/drivers/base/memory.c +++ b/drivers/base/memory.c @@ -303,6 +303,10 @@ static int memory_subsys_offline(struct device *dev) if (mem->state == MEM_OFFLINE) return 0; + /* Can't offline block with non-present sections */ + if (mem->section_count != sections_per_block) + return -EINVAL; + return memory_block_change_state(mem, MEM_OFFLINE, MEM_ONLINE); } -- cgit