Unverified Commit 9d317a54 authored by Krishna Chomal's avatar Krishna Chomal Committed by Ilpo Järvinen
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platform/x86: hp-wmi: fix fan table parsing 



For Victus S devices, the BIOS fan table header was being incorrectly
parsed as:
struct {
	u8 unknown;
	u8 num_entries;
}

The first field should be num_fans and the second should be unknown. It
is pure coincidence that interpreting an "unknown" field as "num_entries"
worked on multiple device, however for board 8D87 (in an upcoming patch),
this assumption fails, and the hp-wmi driver fails to load.

We fix this by correcting the header definition and compensating for
num_entries by parsing each entry of the fan table until an all-NULL row
is obtained, mirroring the behavior of OMEN Gaming Hub on Windows.

Fixes: 46be1453 ("platform/x86: hp-wmi: add manual fan control for Victus S models")
Signed-off-by: default avatarKrishna Chomal <krishna.chomal108@gmail.com>
Link: https://patch.msgid.link/20260410191039.125659-2-krishna.chomal108@gmail.com


Reviewed-by: default avatarIlpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: default avatarIlpo Järvinen <ilpo.jarvinen@linux.intel.com>
parent 92c36b63

drivers/platform/x86/hp/hp-wmi.c

+33 −8
Original line number Diff line number Diff line
@@ -469,14 +469,14 @@ struct hp_wmi_hwmon_priv { 
};



struct victus_s_fan_table_header {

	u8 num_fans;

	u8 unknown;

	u8 num_entries;

} __packed;



struct victus_s_fan_table_entry {

	u8 cpu_rpm;

	u8 gpu_rpm;

	u8 unknown;

	u8 noise_db;

} __packed;



struct victus_s_fan_table {
@@ -2563,7 +2563,9 @@ static int hp_wmi_setup_fan_settings(struct hp_wmi_hwmon_priv *priv) 
	u8 fan_data[128] = { 0 };

	struct victus_s_fan_table *fan_table;

	u8 min_rpm, max_rpm;

	int gpu_delta, ret;

	u8 cpu_rpm, gpu_rpm, noise_db;

	int gpu_delta, i, num_entries, ret;

	size_t header_size, entry_size;



	/* Default behaviour on hwmon init is automatic mode */

	priv->mode = PWM_MODE_AUTO;
@@ -2578,13 +2580,36 @@ static int hp_wmi_setup_fan_settings(struct hp_wmi_hwmon_priv *priv) 
		return ret;



	fan_table = (struct victus_s_fan_table *)fan_data;

	if (fan_table->header.num_entries == 0 ||

	    sizeof(struct victus_s_fan_table_header) +

	    sizeof(struct victus_s_fan_table_entry) * fan_table->header.num_entries > sizeof(fan_data))

	if (fan_table->header.num_fans == 0)

		return -EINVAL;



	header_size = sizeof(struct victus_s_fan_table_header);

	entry_size = sizeof(struct victus_s_fan_table_entry);

	num_entries = (sizeof(fan_data) - header_size) / entry_size;

	min_rpm = U8_MAX;

	max_rpm = 0;



	for (i = 0 ; i < num_entries ; i++) {

		cpu_rpm = fan_table->entries[i].cpu_rpm;

		gpu_rpm = fan_table->entries[i].gpu_rpm;

		noise_db = fan_table->entries[i].noise_db;



		/*

		 * On some devices, the fan table is truncated with an all-zero row,

		 * hence we stop parsing here.

		 */

		if (cpu_rpm == 0 && gpu_rpm == 0 && noise_db == 0)

			break;



		if (cpu_rpm < min_rpm)

			min_rpm = cpu_rpm;

		if (cpu_rpm > max_rpm)

			max_rpm = cpu_rpm;

	}



	if (min_rpm == U8_MAX || max_rpm == 0)

		return -EINVAL;



	min_rpm = fan_table->entries[0].cpu_rpm;

	max_rpm = fan_table->entries[fan_table->header.num_entries - 1].cpu_rpm;

	gpu_delta = fan_table->entries[0].gpu_rpm - fan_table->entries[0].cpu_rpm;

	priv->min_rpm = min_rpm;

	priv->max_rpm = max_rpm;