Re: [PATCH] cpufreq: acpi: Allow new dynamics attributes to be added to acpi_cpufreq_attr

On Thu, Mar 3, 2016 at 6:40 AM, Viresh Kumar viresh.kumar@linaro.org wrote:

acpi_cpufreq_attr contains at least one dynamically populated (removed) attribute today, cpb. But the code isn't friendly enough for new attributes to be populated in a similar way.

Make some changes to allow new attributes to be easily added to the struct.

Signed-off-by: Viresh Kumar viresh.kumar@linaro.org

Srinivas,

This should make it easy for you to add another dynamic entry into the acpi_cpufreq_attr structure.

drivers/cpufreq/acpi-cpufreq.c | 19 +++++++++---------- 1 file changed, 9 insertions(+), 10 deletions(-)

diff --git a/drivers/cpufreq/acpi-cpufreq.c b/drivers/cpufreq/acpi-cpufreq.c index 59a7b380fbe2..c37617ddcc9e 100644 --- a/drivers/cpufreq/acpi-cpufreq.c +++ b/drivers/cpufreq/acpi-cpufreq.c @@ -866,7 +866,7 @@ static struct freq_attr *acpi_cpufreq_attr[] = { &cpufreq_freq_attr_scaling_available_freqs, &freqdomain_cpus, #ifdef CONFIG_X86_ACPI_CPUFREQ_CPB

•   &cpb,
  

•   NULL,   /* Extra space for cpb if required */
  

#endif NULL, };

@@ -917,6 +917,7 @@ static void acpi_cpufreq_boost_exit(void)

static int __init acpi_cpufreq_init(void) {

•   struct freq_attr **attr;
    int ret;
  
    if (acpi_disabled)
  

@@ -932,6 +933,10 @@ static int __init acpi_cpufreq_init(void) if (ret) return ret;

•   /* Find first empty entry */
  

•   for (attr = acpi_cpufreq_attr; *attr; attr++)
  

•           ;
  

#ifdef CONFIG_X86_ACPI_CPUFREQ_CPB /* this is a sysfs file with a strange name and an even stranger * semantic - per CPU instantiation, but system global effect. @@ -939,17 +944,11 @@ static int __init acpi_cpufreq_init(void) * only if configured. This is considered legacy code, which * will probably be removed at some point in the future. */

•   if (!check_amd_hwpstate_cpu(0)) {
  

•           struct freq_attr **attr;
  

•   if (check_amd_hwpstate_cpu(0))
  

•           *attr++ = &cpb;
  

•   else
            pr_debug("CPB unsupported, do not expose it\n");
  
  

•           for (attr = acpi_cpufreq_attr; *attr; attr++)
  

•                   if (*attr == &cpb) {
  

•                           *attr = NULL;
  

•                           break;
  

•                   }
  

•   }
  

#endif acpi_cpufreq_boost_init();

OK, this makes sense.

The table definition starts to look somewhat ugly with all of those NULLs at the end, but then adding the base_frequency thing to it would be easy.

Srinivas, can you please take this and rebase your patch on top of it? Or if you prefer, I can take it into my linux-next branch.

Thanks, Rafael