Commit dd7c46d6 authored by Rafael J. Wysocki's avatar Rafael J. Wysocki
Browse files

Revert "cpufreq: intel_pstate: Process HWP Guaranteed change notification" 



Revert commit d0e936ad ("cpufreq: intel_pstate: Process HWP
Guaranteed change notification"), because it causes a NULL pointer
dereference to occur on Lenovo X1 gen9 laptops due to an HWP
guaranteed performance change interrupt arriving prematurely.

This feature will be revisited in the next cycle.

Reported-by: default avatarJens Axboe <axboe@kernel.dk>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 4bf8e582

drivers/cpufreq/intel_pstate.c

+0 −39
Original line number Diff line number Diff line
@@ -32,7 +32,6 @@ 
#include <asm/cpu_device_id.h>

#include <asm/cpufeature.h>

#include <asm/intel-family.h>

#include "../drivers/thermal/intel/thermal_interrupt.h"



#define INTEL_PSTATE_SAMPLING_INTERVAL	(10 * NSEC_PER_MSEC)
@@ -220,7 +219,6 @@ struct global_params { 
 * @sched_flags:	Store scheduler flags for possible cross CPU update

 * @hwp_boost_min:	Last HWP boosted min performance

 * @suspended:		Whether or not the driver has been suspended.

 * @hwp_notify_work:	workqueue for HWP notifications.

 *

 * This structure stores per CPU instance data for all CPUs.

 */
@@ -259,7 +257,6 @@ struct cpudata { 
	unsigned int sched_flags;

	u32 hwp_boost_min;

	bool suspended;

	struct delayed_work hwp_notify_work;

};



static struct cpudata **all_cpu_data;
@@ -1628,40 +1625,6 @@ static void intel_pstate_sysfs_hide_hwp_dynamic_boost(void) 


/************************** sysfs end ************************/



static void intel_pstate_notify_work(struct work_struct *work)

{

	mutex_lock(&intel_pstate_driver_lock);

	cpufreq_update_policy(smp_processor_id());

	wrmsrl(MSR_HWP_STATUS, 0);

	mutex_unlock(&intel_pstate_driver_lock);

}



void notify_hwp_interrupt(void)

{

	unsigned int this_cpu = smp_processor_id();

	struct cpudata *cpudata;

	u64 value;



	if (!hwp_active || !boot_cpu_has(X86_FEATURE_HWP_NOTIFY))

		return;



	rdmsrl(MSR_HWP_STATUS, value);

	if (!(value & 0x01))

		return;



	cpudata = all_cpu_data[this_cpu];

	schedule_delayed_work_on(this_cpu, &cpudata->hwp_notify_work, msecs_to_jiffies(10));

}



static void intel_pstate_enable_hwp_interrupt(struct cpudata *cpudata)

{

	/* Enable HWP notification interrupt for guaranteed performance change */

	if (boot_cpu_has(X86_FEATURE_HWP_NOTIFY)) {

		INIT_DELAYED_WORK(&cpudata->hwp_notify_work, intel_pstate_notify_work);

		wrmsrl_on_cpu(cpudata->cpu, MSR_HWP_INTERRUPT, 0x01);

	}

}



static void intel_pstate_hwp_enable(struct cpudata *cpudata)

{

	/* First disable HWP notification interrupt as we don't process them */
@@ -1671,8 +1634,6 @@ static void intel_pstate_hwp_enable(struct cpudata *cpudata) 
	wrmsrl_on_cpu(cpudata->cpu, MSR_PM_ENABLE, 0x1);

	if (cpudata->epp_default == -EINVAL)

		cpudata->epp_default = intel_pstate_get_epp(cpudata, 0);



	intel_pstate_enable_hwp_interrupt(cpudata);

}



static int atom_get_min_pstate(void)