HID: amd_sfh: Add sync across amd sfh work functions

The process of the report is delegated across different work functions.
Hence, add a sync mechanism to protect SFH work data across functions.

Fixes: 4b2c53d ("SFH:Transport Driver to add support of AMD Sensor Fusion Hub (SFH)")
Reported-by: Matthew Schwartz <[email protected]>
Closes: https://lore.kernel.org/all/[email protected]/
Tested-by: Prakruthi SP <[email protected]>
Co-developed-by: Akshata MukundShetty <[email protected]>
Signed-off-by: Akshata MukundShetty <[email protected]>
Signed-off-by: Basavaraj Natikar <[email protected]>
Reviewed-by: Mario Limonciello (AMD) <[email protected]>
Signed-off-by: Jiri Kosina <[email protected]>

Author: basuamd

drivers/hid/amd-sfh-hid/amd_sfh_client.c

@@ -39,8 +39,12 @@ int amd_sfh_get_report(struct hid_device *hid, int report_id, int report_type)
 	struct amdtp_hid_data *hid_data = hid->driver_data;
 	struct amdtp_cl_data *cli_data = hid_data->cli_data;
 	struct request_list *req_list = &cli_data->req_list;
+	struct amd_input_data *in_data = cli_data->in_data;
+	struct amd_mp2_dev *mp2;
 	int i;
 
+	mp2 = container_of(in_data, struct amd_mp2_dev, in_data);
+	guard(mutex)(&mp2->lock);
 	for (i = 0; i < cli_data->num_hid_devices; i++) {
 		if (cli_data->hid_sensor_hubs[i] == hid) {
 			struct request_list *new = kzalloc(sizeof(*new), GFP_KERNEL);
@@ -75,6 +79,8 @@ void amd_sfh_work(struct work_struct *work)
 	u8 report_id, node_type;
 	u8 report_size = 0;
 
+	mp2 = container_of(in_data, struct amd_mp2_dev, in_data);
+	guard(mutex)(&mp2->lock);
 	req_node = list_last_entry(&req_list->list, struct request_list, list);
 	list_del(&req_node->list);
 	current_index = req_node->current_index;
@@ -83,7 +89,6 @@ void amd_sfh_work(struct work_struct *work)
 	node_type = req_node->report_type;
 	kfree(req_node);
 
-	mp2 = container_of(in_data, struct amd_mp2_dev, in_data);
 	mp2_ops = mp2->mp2_ops;
 	if (node_type == HID_FEATURE_REPORT) {
 		report_size = mp2_ops->get_feat_rep(sensor_index, report_id,
@@ -107,6 +112,8 @@ void amd_sfh_work(struct work_struct *work)
 	cli_data->cur_hid_dev = current_index;
 	cli_data->sensor_requested_cnt[current_index] = 0;
 	amdtp_hid_wakeup(cli_data->hid_sensor_hubs[current_index]);
+	if (!list_empty(&req_list->list))
+		schedule_delayed_work(&cli_data->work, 0);
 }
 
 void amd_sfh_work_buffer(struct work_struct *work)
@@ -117,9 +124,10 @@ void amd_sfh_work_buffer(struct work_struct *work)
 	u8 report_size;
 	int i;
 
+	mp2 = container_of(in_data, struct amd_mp2_dev, in_data);
+	guard(mutex)(&mp2->lock);
 	for (i = 0; i < cli_data->num_hid_devices; i++) {
 		if (cli_data->sensor_sts[i] == SENSOR_ENABLED) {
-			mp2 = container_of(in_data, struct amd_mp2_dev, in_data);
 			report_size = mp2->mp2_ops->get_in_rep(i, cli_data->sensor_idx[i],
 							       cli_data->report_id[i], in_data);
 			hid_input_report(cli_data->hid_sensor_hubs[i], HID_INPUT_REPORT,

drivers/hid/amd-sfh-hid/amd_sfh_common.h

@@ -10,6 +10,7 @@
 #ifndef AMD_SFH_COMMON_H
 #define AMD_SFH_COMMON_H
 
+#include <linux/mutex.h>
 #include <linux/pci.h>
 #include "amd_sfh_hid.h"
 
@@ -59,6 +60,8 @@ struct amd_mp2_dev {
 	u32 mp2_acs;
 	struct sfh_dev_status dev_en;
 	struct work_struct work;
+	/* mp2 to protect data */
+	struct mutex lock;
 	u8 init_done;
 	u8 rver;
 };

drivers/hid/amd-sfh-hid/amd_sfh_pcie.c

@@ -466,6 +466,10 @@ static int amd_mp2_pci_probe(struct pci_dev *pdev, const struct pci_device_id *i
 	if (!privdata->cl_data)
 		return -ENOMEM;
 
+	rc = devm_mutex_init(&pdev->dev, &privdata->lock);
+	if (rc)
+		return rc;
+
 	privdata->sfh1_1_ops = (const struct amd_sfh1_1_ops *)id->driver_data;
 	if (privdata->sfh1_1_ops) {
 		if (boot_cpu_data.x86 >= 0x1A)