Re: [PATCHv4] platform/x86: hp-wmi: Fix platform profile option switch bug on Omen and Victus laptops

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Am 27.06.24 um 00:04 schrieb Alexis Belmonte:

Fix a platform profile option switch/getter bug on some Omen and Victus laptops

Hi,

the preferred line length inside commit descriptions is 75 characters per line,
please add some line breaks where necessary.

dismissing userspace choice when selecting performance mode in inadequate
conditions (e.g. by being disconnected from the AC power plug) by

    -  hooking an ACPI notify handler through the
       omen_register_powersource_notifier_handler method that listens to AC
       power source changes (plugging in/out the AC power plug)

    -  keeping an intermediate active_platform_profile variable that is
       set when userspace changes the platform profile setting

    -  restoring the selected platform profile kept in
       active_platform_profile when AC power is plugged back into the
       laptop, unless if the user decided to alter the platform profile mid-way

This ensures that the driver follows the principles defined in the Platform
Profile Selection page of the Kernel documentation on those kind of laptops;
which is to not "(...) let userspace know about any sub-optimal conditions
which are impeding reaching the requested performance level".

Since the Omen and Victus laptops share the same embedded controller system,
the fix is applicable to both categories of laptops.

Signed-off-by: Alexis Belmonte <alexbelm48@xxxxxxxxx>
---
V1 -> V2: - Use register_acpi_notifier and unregister_acpi_notifier instead of
             hooking straight through ACPI node \\_SB.ADP1
V2 -> V3: - Rely on power_supply_is_system_supplied() instead of an EC-specific
             field to determine if the laptop is plugged in
           - Refactor omen_powersource_notify_handler to omen_powersource_event
           - Refactor omen_powersource_register_notifier_handler to
             omen_register_powersource_event_handler
           - Use a mutex to protect the active_platform_profile variable from
             being altered while the handler is executed
V3 -> V4: - Remove the unnecessary enum declaration remains from the initial
             implementation
---
  drivers/platform/x86/hp/hp-wmi.c | 184 +++++++++++++++++++++++++++++--
  1 file changed, 172 insertions(+), 12 deletions(-)

diff --git a/drivers/platform/x86/hp/hp-wmi.c b/drivers/platform/x86/hp/hp-wmi.c
index 5fa553023842..2f57dfe6ab9c 100644
--- a/drivers/platform/x86/hp/hp-wmi.c
+++ b/drivers/platform/x86/hp/hp-wmi.c
@@ -24,6 +24,7 @@
  #include <linux/platform_profile.h>
  #include <linux/hwmon.h>
  #include <linux/acpi.h>
+#include <linux/power_supply.h>
  #include <linux/rfkill.h>
  #include <linux/string.h>
  #include <linux/dmi.h>
@@ -261,8 +262,12 @@ static const struct key_entry hp_wmi_keymap[] = {

  static struct input_dev *hp_wmi_input_dev;
  static struct input_dev *camera_shutter_input_dev;
+

This change is unnecessary, please drop it.

  static struct platform_device *hp_wmi_platform_dev;
  static struct platform_profile_handler platform_profile_handler;
+static struct notifier_block platform_power_source_nb;
+DEFINE_MUTEX(active_platform_profile_lock);

Checkpatch complains about a "DEFINE_MUTEX definition without comment", so please add a short
comment explaining why this mutex exists.

Also please move the mutex definition away from the rest of the variable definitions.

+static enum platform_profile_option active_platform_profile;
  static bool platform_profile_support;
  static bool zero_insize_support;

@@ -1194,8 +1199,7 @@ static int __init hp_wmi_rfkill2_setup(struct platform_device *device)
  	return err;
  }

-static int platform_profile_omen_get(struct platform_profile_handler *pprof,
-				     enum platform_profile_option *profile)
+static int platform_profile_omen_get_ec(enum platform_profile_option *profile)
  {
  	int tp;

@@ -1223,6 +1227,30 @@ static int platform_profile_omen_get(struct platform_profile_handler *pprof,
  	return 0;
  }

+static int platform_profile_omen_get(struct platform_profile_handler *pprof,
+				     enum platform_profile_option *profile)
+{
+	enum platform_profile_option selected_platform_profile;
+
+	/*
+	 * We directly return the stored platform profile, as the embedded
+	 * controller will not accept switching to the performance option when
+	 * the conditions are not met (e.g. the laptop is not plugged in).
+	 *
+	 * If we directly return what the EC reports, the platform profile will
+	 * immediately "switch back" to normal mode, which is against the
+	 * expected behaviour from a userspace point of view, as described in
+	 * the Platform Profile Section page of the kernel documentation.
+	 *
+	 * See also omen_powersource_event.
+	 */
+	mutex_lock(&active_platform_profile_lock);
+	selected_platform_profile = active_platform_profile;
+	mutex_unlock(&active_platform_profile_lock);
+
+	return selected_platform_profile;
+}
+
  static bool has_omen_thermal_profile_ec_timer(void)
  {
  	const char *board_name = dmi_get_system_info(DMI_BOARD_NAME);
@@ -1248,7 +1276,7 @@ inline int omen_thermal_profile_ec_timer_set(u8 value)
  static int platform_profile_omen_set(struct platform_profile_handler *pprof,
  				     enum platform_profile_option profile)
  {
-	int err, tp, tp_version;
+	int err = 0, tp, tp_version;

Please place the definition of "int err = 0" on its own line.

  	enum hp_thermal_profile_omen_flags flags = 0;

  	tp_version = omen_get_thermal_policy_version();
@@ -1279,14 +1307,16 @@ static int platform_profile_omen_set(struct platform_profile_handler *pprof,
  		return -EOPNOTSUPP;
  	}

+	mutex_lock(&active_platform_profile_lock);
+
  	err = omen_thermal_profile_set(tp);
  	if (err < 0)
-		return err;
+		goto unlock_and_return;

  	if (has_omen_thermal_profile_ec_timer()) {
  		err = omen_thermal_profile_ec_timer_set(0);
  		if (err < 0)
-			return err;
+			goto unlock_and_return;

  		if (profile == PLATFORM_PROFILE_PERFORMANCE)
  			flags = HP_OMEN_EC_FLAGS_NOTIMER |
@@ -1294,10 +1324,15 @@ static int platform_profile_omen_set(struct platform_profile_handler *pprof,

  		err = omen_thermal_profile_ec_flags_set(flags);
  		if (err < 0)
-			return err;
+			goto unlock_and_return;
  	}

-	return 0;
+	active_platform_profile = profile;
+
+unlock_and_return:
+	mutex_unlock(&active_platform_profile_lock);

Can you please rename this goto label to something like "out_unlock"?

+
+	return err;
  }

  static int thermal_profile_get(void)
@@ -1381,8 +1416,8 @@ static bool is_victus_thermal_profile(void)
  			    board_name) >= 0;
  }

-static int platform_profile_victus_get(struct platform_profile_handler *pprof,
-				     enum platform_profile_option *profile)
+static int platform_profile_victus_get_ec(
+	enum platform_profile_option *profile)

Checkpatch complains that "Lines should not end with a '('", please fix.

  {
  	int tp;

@@ -1407,10 +1442,27 @@ static int platform_profile_victus_get(struct platform_profile_handler *pprof,
  	return 0;
  }

+static int platform_profile_victus_get(struct platform_profile_handler *pprof,
+				       enum platform_profile_option *profile)
+{
+	enum platform_profile_option selected_platform_profile;
+
+	/*
+	 * Same as for platform_profile_omen_get -- I still decided to keep
+	 * it as a separate implementation if we need to add Victus-specific
+	 * behaviour/logic in the future
+	 */

Personally, i do not agree with this opinion, but its up to the driver maintainer to
decide here.

+	mutex_lock(&active_platform_profile_lock);
+	selected_platform_profile = active_platform_profile;
+	mutex_unlock(&active_platform_profile_lock);
+
+	return selected_platform_profile;
+}
+
  static int platform_profile_victus_set(struct platform_profile_handler *pprof,
-				     enum platform_profile_option profile)
+				       enum platform_profile_option profile)
  {
-	int err, tp;
+	int err = 0, tp;

Unnecessary change, please drop.


  	switch (profile) {
  	case PLATFORM_PROFILE_PERFORMANCE:
@@ -1426,13 +1478,106 @@ static int platform_profile_victus_set(struct platform_profile_handler *pprof,
  		return -EOPNOTSUPP;
  	}

+	mutex_lock(&active_platform_profile_lock);
+
  	err = omen_thermal_profile_set(tp);
  	if (err < 0)
-		return err;
+		goto unlock_and_return;
+
+	active_platform_profile = profile;
+
+unlock_and_return:
+	mutex_unlock(&active_platform_profile_lock);

I think you can drop this goto label here and just unlock the mutex and return if an error occured.
This would also fix the issue of still returning 0 even when an error occured.


  	return 0;
  }

+static int omen_powersource_event(struct notifier_block *nb,
+					   unsigned long value,
+					   void *data)
+{

Checkpatch: "Alignment should match open parenthesis".

+	struct acpi_bus_event *event_entry = data;
+	enum platform_profile_option selected_platform_profile;
+	enum platform_profile_option actual_profile;
+	int err;
+
+	if (strcmp(event_entry->device_class, "ac_adapter") != 0)
+		return NOTIFY_DONE;

Maybe use a macro here for "ac_adapter"?

+
+	pr_debug("Received power source device event\n");
+
+	if (is_omen_thermal_profile())
+		err = platform_profile_omen_get_ec(&actual_profile);
+	else if (is_victus_thermal_profile())
+		err = platform_profile_victus_get_ec(&actual_profile);

Please use braces here for both if-statements and the else-statement.

+
+	if (err < 0) {
+		pr_warn("Failed to read current platform profile (%d)\n", err);
+		return NOTIFY_BAD;
+	}

I do not think that returning NOTIFY_BAD is a good idea in this case, as this would
stop any other event consumers from handling the event.

Maybe returning NOTIFY_DONE together with a comment would be better here?

+
+	/*
+	 * We don't want the handler to overwrite the newly set platform
+	 * profile if the user has changed it in the meantime (thanks Armin!)
+	 */
+	if (!mutex_trylock(&active_platform_profile_lock))
+		return NOTIFY_DONE;

This construct might cause you to miss power source events when the event is received
right after omen_thermal_profile_set() was called but before the mutex has been unlocked.

Please unconditionally take the mutex before calling platform_profile_omen/victus_get_ec()
and drop it _after_ updating the EC platform profile.

This means that you have to provide helper functions for profile_get()/profile_set() which
do not take the mutex.

+
+	selected_platform_profile = active_platform_profile;
+	mutex_unlock(&active_platform_profile_lock);
+
+	/*
+	 * If we're back on AC and that the user-chosen power profile is
+	 * different from what the EC reports, we restore the user-chosen
+	 * one.
+	 */
+	if (power_supply_is_system_supplied() >= 0 ||
+	    selected_platform_profile == actual_profile)
+		return NOTIFY_DONE;
+
+	err = platform_profile_handler.profile_set(&platform_profile_handler,
+						   active_platform_profile);
+	if (err < 0) {
+		pr_warn("Failed to restore platform profile (%d)\n", err);
+		return NOTIFY_BAD;

Same as the other NOTIFY_BAD.

+	}
+
+	return NOTIFY_OK;
+}
+
+static void omen_register_powersource_event_handler(void)
+{
+	int err;
+	acpi_status status;
+
+	if (is_omen_thermal_profile())
+		err = platform_profile_omen_get_ec(&active_platform_profile);
+	else if (is_victus_thermal_profile())
+		err = platform_profile_victus_get_ec(&active_platform_profile);
+
+	if (err < 0) {
+		pr_warn("Failed to retrieve active platform profile (%d)\n",
+			err);
+		active_platform_profile = PLATFORM_PROFILE_BALANCED;
+	}
+
+	platform_power_source_nb.notifier_call = omen_powersource_event;
+	status = register_acpi_notifier(&platform_power_source_nb);
+
+	if (ACPI_FAILURE(status))
+		pr_warn("Failed to install ACPI power source notify handler\n");
+}
+
+static void omen_unregister_powersource_event_handler(void)
+{
+	acpi_status status;
+
+	status = unregister_acpi_notifier(&platform_power_source_nb);
+
+	if (ACPI_FAILURE(status))
+		pr_err("Failed to remove ACPI power source notify handler\n");
+}
+
  static int thermal_profile_setup(void)
  {
  	int err, tp;
@@ -1534,6 +1679,15 @@ static int __init hp_wmi_bios_setup(struct platform_device *device)

  	thermal_profile_setup();

+	/*
+	 * Query the platform profile once to know which last power profile
+	 * was set.
+	 */
+	err = platform_profile_handler.profile_get(&platform_profile_handler,
+						   &active_platform_profile);

You have to initialize active_platform_profile before calling thermal_profile_setup(), otherwise
a very timely user might change the platform profile without active_platform_profile being set.

Also it would make sense to just drop the active_platform_profile initialization in
omen_register_powersource_event_handler() then.

+	if (err < 0)
+		return err;
+
  	return 0;
  }

@@ -1758,6 +1912,9 @@ static int __init hp_wmi_init(void)
  			goto err_unregister_device;
  	}

+	if (is_omen_thermal_profile() || is_victus_thermal_profile())
+		omen_register_powersource_event_handler();
+
  	return 0;

  err_unregister_device:
@@ -1772,6 +1929,9 @@ module_init(hp_wmi_init);

  static void __exit hp_wmi_exit(void)
  {
+	if (is_omen_thermal_profile() || is_victus_thermal_profile())
+		omen_unregister_powersource_event_handler();

You have to check if the event handler was registered successfully before
unregistering it.

Thanks,
Armin Wolf

+
  	if (wmi_has_guid(HPWMI_EVENT_GUID))
  		hp_wmi_input_destroy();






[Index of Archives]     [Linux Kernel Development]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux