fpsensor: Use consistent unsigned type for finger index

This is a followup to https://crrev.com/c/3872809, which changed the
variable tracking the number of fingers to a consistent type (uint16_t).

BRANCH=none
BUG=b:244781166
TEST=./test/run_device_tests.py --board dartmonkey
         => PASS
TEST=./test/run_device_tests.py --board bloonchipper
         => PASS
TEST=Flash firmware on gimble, enroll, lock, unlock

Change-Id: I1f414fc2bf3ccb229ad074f73eaf4a51fa252bdb
Signed-off-by: Tom Hughes <[email protected]>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/4382560
Reviewed-by: Yi Chou <[email protected]>

Author: thughes

common/fpsensor/fpsensor.cc

@@ -412,7 +412,7 @@ static enum ec_status fp_command_frame(struct host_cmd_handler_args *args)
 	const auto *params =
 		static_cast<const struct ec_params_fp_frame *>(args->params);
 	void *out = args->response;
-	uint32_t idx = FP_FRAME_GET_BUFFER_INDEX(params->offset);
+	uint16_t idx = FP_FRAME_GET_BUFFER_INDEX(params->offset);
 	uint32_t offset = params->offset & FP_FRAME_OFFSET_MASK;
 	uint32_t size = params->size;
 	uint16_t fgr;
@@ -579,7 +579,7 @@ static enum ec_status fp_command_template(struct host_cmd_handler_args *args)
 	uint32_t size = params->size & ~FP_TEMPLATE_COMMIT;
 	bool xfer_complete = params->size & FP_TEMPLATE_COMMIT;
 	uint32_t offset = params->offset;
-	uint32_t idx = templ_valid;
+	uint16_t idx = templ_valid;
 	uint8_t key[SBP_ENC_KEY_LEN];
 	struct ec_fp_template_encryption_metadata *enc_info;
 	int ret;

common/fpsensor/fpsensor_state.cc

@@ -69,7 +69,7 @@ void fp_task_simulate(void)
 		task_wait_event(timeout_us);
 }
 
-void fp_clear_finger_context(int idx)
+void fp_clear_finger_context(uint16_t idx)
 {
 	always_memset(fp_template[idx], 0, sizeof(fp_template[0]));
 	always_memset(fp_positive_match_salt[idx], 0,
@@ -83,15 +83,13 @@ void fp_clear_finger_context(int idx)
  */
 static void _fp_clear_context(void)
 {
-	int idx;
-
 	templ_valid = 0;
 	templ_dirty = 0;
 	always_memset(fp_buffer, 0, sizeof(fp_buffer));
 	always_memset(fp_enc_buffer, 0, sizeof(fp_enc_buffer));
 	always_memset(user_id, 0, sizeof(user_id));
 	fp_disable_positive_match_secret(&positive_match_secret_state);
-	for (idx = 0; idx < FP_MAX_FINGER_COUNT; idx++)
+	for (uint16_t idx = 0; idx < FP_MAX_FINGER_COUNT; idx++)
 		fp_clear_finger_context(idx);
 }
 

include/fpsensor_state.h

@@ -91,7 +91,7 @@ void fp_task_simulate(void);
  *
  * @param idx the index of the template to clear.
  */
-void fp_clear_finger_context(int idx);
+void fp_clear_finger_context(uint16_t idx);
 
 /**
  * Clear all fingerprint templates associated with the current user id and