Commit c3274763 authored by Srivatsa S. Bhat's avatar Srivatsa S. Bhat Committed by Rafael J. Wysocki

cpufreq: powernow-k8: Initialize per-cpu data-structures properly

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=70311Reported-by: default avatarPierre Ossman <pierre@ossman.eu>
Signed-off-by: default avatarSrivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: All applicable <stable@vger.kernel.org>
Acked-by: default avatarViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 6964d91d
...@@ -1076,7 +1076,7 @@ static int powernowk8_cpu_init(struct cpufreq_policy *pol) ...@@ -1076,7 +1076,7 @@ static int powernowk8_cpu_init(struct cpufreq_policy *pol)
{ {
struct powernow_k8_data *data; struct powernow_k8_data *data;
struct init_on_cpu init_on_cpu; struct init_on_cpu init_on_cpu;
int rc; int rc, cpu;
smp_call_function_single(pol->cpu, check_supported_cpu, &rc, 1); smp_call_function_single(pol->cpu, check_supported_cpu, &rc, 1);
if (rc) if (rc)
...@@ -1140,7 +1140,9 @@ static int powernowk8_cpu_init(struct cpufreq_policy *pol) ...@@ -1140,7 +1140,9 @@ static int powernowk8_cpu_init(struct cpufreq_policy *pol)
pr_debug("cpu_init done, current fid 0x%x, vid 0x%x\n", pr_debug("cpu_init done, current fid 0x%x, vid 0x%x\n",
data->currfid, data->currvid); 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; return 0;
...@@ -1155,6 +1157,7 @@ static int powernowk8_cpu_init(struct cpufreq_policy *pol) ...@@ -1155,6 +1157,7 @@ static int powernowk8_cpu_init(struct cpufreq_policy *pol)
static int powernowk8_cpu_exit(struct cpufreq_policy *pol) static int powernowk8_cpu_exit(struct cpufreq_policy *pol)
{ {
struct powernow_k8_data *data = per_cpu(powernow_data, pol->cpu); struct powernow_k8_data *data = per_cpu(powernow_data, pol->cpu);
int cpu;
if (!data) if (!data)
return -EINVAL; return -EINVAL;
...@@ -1165,7 +1168,8 @@ static int powernowk8_cpu_exit(struct cpufreq_policy *pol) ...@@ -1165,7 +1168,8 @@ static int powernowk8_cpu_exit(struct cpufreq_policy *pol)
kfree(data->powernow_table); kfree(data->powernow_table);
kfree(data); kfree(data);
per_cpu(powernow_data, pol->cpu) = NULL; for_each_cpu(cpu, pol->cpus)
per_cpu(powernow_data, cpu) = NULL;
return 0; return 0;
} }
......
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