From 018d4e6ff10954e7ecc05bc4a3193b541827124e Mon Sep 17 00:00:00 2001
From: Pol Henarejos <pol.henarejos@cttc.es>
Date: Mon, 1 Jun 2026 13:17:52 +0200
Subject: [PATCH] Rate-limit core0 card_status polling loops

---
 src/usb/ccid/ccid.c        | 19 +++++++++++++------
 src/usb/hid/hid.c          | 18 ++++++++++++------
 src/usb/lwip/rest_server.c |  8 ++++++++
 3 files changed, 33 insertions(+), 12 deletions(-)

diff --git a/src/usb/ccid/ccid.c b/src/usb/ccid/ccid.c
index 7ef4a20..9d611b0 100644
--- a/src/usb/ccid/ccid.c
+++ b/src/usb/ccid/ccid.c
@@ -345,13 +345,20 @@ void driver_exec_finished_cont_ccid(uint8_t itf, uint16_t size_next, uint16_t of
 }
 
 void ccid_task(void) {
+    const uint32_t status_poll_interval_ms = 1;
+    static uint32_t last_status_poll_ms[8] = {0};
+    uint32_t now_ms = board_millis();
     for (uint8_t itf = 0; itf < ITF_SC_TOTAL; itf++) {
-        int status = card_status(sc_itf_to_usb_itf(itf));
-        if (status == PICOKEYS_OK) {
-            driver_exec_finished_ccid(itf, finished_data_size);
-        }
-        else if (status == PICOKEYS_ERR_BLOCKED) {
-            driver_exec_timeout_ccid(itf);
+        if (itf < (sizeof(last_status_poll_ms) / sizeof(last_status_poll_ms[0])) &&
+            now_ms - last_status_poll_ms[itf] >= status_poll_interval_ms) {
+            last_status_poll_ms[itf] = now_ms;
+            int status = card_status(sc_itf_to_usb_itf(itf));
+            if (status == PICOKEYS_OK) {
+                driver_exec_finished_ccid(itf, finished_data_size);
+            }
+            else if (status == PICOKEYS_ERR_BLOCKED) {
+                driver_exec_timeout_ccid(itf);
+            }
         }
         if (ccid_tx[itf].w_ptr > ccid_tx[itf].r_ptr) {
             if (driver_write_ccid(itf, ccid_tx[itf].buffer + ccid_tx[itf].r_ptr, ccid_tx[itf].w_ptr - ccid_tx[itf].r_ptr) > 0) {
diff --git a/src/usb/hid/hid.c b/src/usb/hid/hid.c
index f5b55aa..c86872c 100644
--- a/src/usb/hid/hid.c
+++ b/src/usb/hid/hid.c
@@ -601,6 +601,8 @@ void driver_exec_finished_cont_hid(uint8_t itf, uint16_t size_next, uint16_t off
 }
 
 void hid_task(void) {
+    const uint32_t status_poll_interval_ms = 1;
+    static uint32_t last_status_poll_ms = 0;
 #ifdef ENABLE_EMULATION
     uint16_t rx_len = emul_read(ITF_HID);
     if (rx_len) {
@@ -620,12 +622,16 @@ void hid_task(void) {
     if (proc_pkt == 0) {
         driver_process_usb_nopacket_hid();
     }
-    int status = card_status(ITF_HID);
-    if (status == PICOKEYS_OK) {
-        driver_exec_finished_hid(finished_data_size);
-    }
-    else if (status == PICOKEYS_ERR_BLOCKED) {
-        send_keepalive();
+    uint32_t now_ms = board_millis();
+    if (now_ms - last_status_poll_ms >= status_poll_interval_ms) {
+        last_status_poll_ms = now_ms;
+        int status = card_status(ITF_HID);
+        if (status == PICOKEYS_OK) {
+            driver_exec_finished_hid(finished_data_size);
+        }
+        else if (status == PICOKEYS_ERR_BLOCKED) {
+            send_keepalive();
+        }
     }
     if (hid_tx[ITF_HID_CTAP].w_ptr > hid_tx[ITF_HID_CTAP].r_ptr && last_write_result[ITF_HID_CTAP] != WRITE_PENDING) {
         if (driver_write_hid(ITF_HID_CTAP, hid_tx[ITF_HID_CTAP].buffer + hid_tx[ITF_HID_CTAP].r_ptr, 64) > 0) {
diff --git a/src/usb/lwip/rest_server.c b/src/usb/lwip/rest_server.c
index c852916..ee763c0 100644
--- a/src/usb/lwip/rest_server.c
+++ b/src/usb/lwip/rest_server.c
@@ -209,6 +209,8 @@ static void send_json_error(rest_conn_t *conn, int status_code, const char *erro
 }
 
 void rest_task(void) {
+    const uint32_t status_poll_interval_ms = 1;
+    static uint32_t last_status_poll_ms = 0;
     if (!rest_core1_job_pending_load()) {
         rest_route_handler_t handler = rest_background_job_pop();
         if (handler != NULL) {
@@ -219,6 +221,12 @@ void rest_task(void) {
         }
         return;
     }
+    uint32_t now_ms = board_millis();
+    if (now_ms - last_status_poll_ms < status_poll_interval_ms) {
+        return;
+    }
+    last_status_poll_ms = now_ms;
+
     int status = card_status(ITF_LWIP);
     if (status != PICOKEYS_OK) {
         return;