diff options
| author | Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> | 2014-02-17 10:48:21 (GMT) |
|---|---|---|
| committer | Jiri Slaby <jslaby@suse.cz> | 2014-03-05 16:13:46 (GMT) |
| commit | 493931434ba8f6d2b9b1ea1cc377c22787bb3bd7 (patch) | |
| tree | 4e9a7d4f13d405d8e605cae69ff4ec0583a0bdc1 /drivers | |
| parent | bbff349264e736651e87bc6937882529b5441d47 (diff) | |
| download | linux-fsl-qoriq-493931434ba8f6d2b9b1ea1cc377c22787bb3bd7.tar.xz | |
cpufreq: powernow-k8: Initialize per-cpu data-structures properly
commit c3274763bfc3bf1ececa269ed6e6c4d7ec1c3e5e upstream.
The powernow-k8 driver maintains a per-cpu data-structure called
powernow_data that is used to perform the frequency transitions.
It initializes this data structure only for the policy->cpu. So,
accesses to this data structure by other CPUs results in various
problems because they would have been uninitialized.
Specifically, if a cpu (!= policy->cpu) invokes the drivers' ->get()
function, it returns 0 as the KHz value, since its per-cpu memory
doesn't point to anything valid. This causes problems during
suspend/resume since cpufreq_update_policy() tries to enforce this
(0 KHz) as the current frequency of the CPU, and this madness gets
propagated to adjust_jiffies() as well. Eventually, lots of things
start breaking down, including the r8169 ethernet card, in one
particularly interesting case reported by Pierre Ossman.
Fix this by initializing the per-cpu data-structures of all the CPUs
in the policy appropriately.
References: https://bugzilla.kernel.org/show_bug.cgi?id=70311
Reported-by: Pierre Ossman <pierre@ossman.eu>
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/cpufreq/powernow-k8.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/drivers/cpufreq/powernow-k8.c b/drivers/cpufreq/powernow-k8.c index 2344a9e..47b6931 100644 --- a/drivers/cpufreq/powernow-k8.c +++ b/drivers/cpufreq/powernow-k8.c @@ -1100,7 +1100,7 @@ static int powernowk8_cpu_init(struct cpufreq_policy *pol) { struct powernow_k8_data *data; struct init_on_cpu init_on_cpu; - int rc; + int rc, cpu; smp_call_function_single(pol->cpu, check_supported_cpu, &rc, 1); if (rc) @@ -1169,7 +1169,9 @@ static int powernowk8_cpu_init(struct cpufreq_policy *pol) pr_debug("cpu_init done, current fid 0x%x, vid 0x%x\n", data->currfid, data->currvid); - per_cpu(powernow_data, pol->cpu) = data; + /* Point all the CPUs in this policy to the same data */ + for_each_cpu(cpu, pol->cpus) + per_cpu(powernow_data, cpu) = data; return 0; @@ -1184,6 +1186,7 @@ err_out: static int powernowk8_cpu_exit(struct cpufreq_policy *pol) { struct powernow_k8_data *data = per_cpu(powernow_data, pol->cpu); + int cpu; if (!data) return -EINVAL; @@ -1194,7 +1197,8 @@ static int powernowk8_cpu_exit(struct cpufreq_policy *pol) kfree(data->powernow_table); kfree(data); - per_cpu(powernow_data, pol->cpu) = NULL; + for_each_cpu(cpu, pol->cpus) + per_cpu(powernow_data, cpu) = NULL; return 0; } |