Merge branch 'cursor/igiRadio-ios-app' into HEAD

Software/components/core/src/BiquadDesign.cpp

@@ -82,12 +82,20 @@ BiquadCoefficients designPeakingEq(FrequencyHz center, GainDb gain,
     const float a1 = -2.0F * cosOmega;
     const float a2 = 1.0F - alpha / a;
 
+    // RBJ's cookbook form subtracts the feedback terms
+    // (y = ... - (a1/a0) y[n-1] - (a2/a0) y[n-2]); the ADAU1701 Param EQ
+    // cell's A0/A1 registers add them instead (y = ... + A0 y[n-1] +
+    // A1 y[n-2]), so the normalized RBJ a1/a2 must be negated when they
+    // land in A0/A1. Without this, any nonzero gain applies positive
+    // instead of negative feedback at the band's pole, so the biquad's
+    // state diverges and rails to a constant (inaudible DC) value --
+    // root cause of the 2026-08-25 total-silence-on-any-EQ-change bug.
     return BiquadCoefficients{
         .b0 = b0 / a0,
         .b1 = b1 / a0,
         .b2 = b2 / a0,
-        .a0 = a1 / a0,
-        .a1 = a2 / a0,
+        .a0 = -(a1 / a0),
+        .a1 = -(a2 / a0),
     };
 }
 

Software/components/core/test/biquad_design_test.cpp

@@ -54,6 +54,55 @@ namespace {
     return EXIT_SUCCESS;
 }
 
+/*
+ * The ADAU1701 Param EQ cell's A0/A1 registers ADD the feedback terms
+ * (y = ... + A0 y[n-1] + A1 y[n-2]), unlike the RBJ cookbook's native
+ * subtractive form. Denominator 1 - A0 z^-1 - A1 z^-2 = 0 has poles at the
+ * roots of z^2 - A0 z - A1 = 0; by the Jury test for a monic real quadratic
+ * z^2 + c1 z + c0 (c1 = -A0, c0 = -A1), both poles lie strictly inside the
+ * unit circle iff |A1| < 1, A0 + A1 < 1, and A0 - A1 > -1. A missing
+ * negation when mapping the RBJ a1/a2 into A0/A1 (2026-08-25 total-silence
+ * regression) fails this for real gain/Q combinations, so this guards
+ * against that class of bug rather than just checking magnitudes.
+ */
+[[nodiscard]] bool isAdau1701Stable(const core::BiquadCoefficients &c) noexcept
+{
+    return std::fabs(c.a1) < 1.0F && (c.a0 + c.a1) < 1.0F
+        && (c.a0 - c.a1) > -1.0F;
+}
+
+[[nodiscard]] int runPeakingStabilityTest()
+{
+    const struct
+    {
+        std::uint32_t hz;
+        float dbGain;
+        float q;
+    } cases[] = {
+        {100U, 9.0F, 0.9F},   // bass-enhance band 1 at max level
+        {400U, 3.0F, 1.0F},   // bass-enhance band 2 at max level
+        {1000U, -1.5F, 1.0F}, // stereo-enhance band 3 at max level
+        {3000U, 2.0F, 1.0F},  // stereo-enhance band 4 at max level
+        {8000U, 4.0F, 1.0F},  // stereo-enhance band 5 at max level
+        {1000U, 12.0F, 10.0F}, // GainDb::kMaxDb at high Q
+        {1000U, -96.0F, 0.2F}, // near GainDb::kMinDb at low Q
+    };
+
+    for (const auto &tc : cases) {
+        const auto center = core::FrequencyHz::tryFromHz(tc.hz);
+        const auto gain = core::GainDb::tryFromDb(tc.dbGain);
+        const core::BiquadCoefficients peaking =
+            core::designPeakingEq(*center, *gain, tc.q);
+        if (!isAdau1701Stable(peaking)) {
+            std::cerr << "unstable ADAU1701 biquad for " << tc.hz << " Hz, "
+                      << tc.dbGain << " dB, Q=" << tc.q << ": a0=" << peaking.a0
+                      << " a1=" << peaking.a1 << '\n';
+            return EXIT_FAILURE;
+        }
+    }
+    return EXIT_SUCCESS;
+}
+
 } // namespace
 
 int main()
@@ -64,5 +113,8 @@ int main()
     if (runFlatBiquadTest() != EXIT_SUCCESS) {
         return EXIT_FAILURE;
     }
+    if (runPeakingStabilityTest() != EXIT_SUCCESS) {
+        return EXIT_FAILURE;
+    }
     return EXIT_SUCCESS;
 }

Software/components/net/src/SigmaStudioTcpServer.cpp

@@ -494,8 +494,19 @@ void SigmaStudioTcpServer::stop() noexcept
         vTaskDelete(task_);
         task_ = nullptr;
     }
-    activeListenFd().store(-1, std::memory_order_release);
     if (listenFd_ >= 0) {
+        // Only clear the singleton if it still points at *our* fd: every
+        // boot path constructs this as a named local, start()s it, then
+        // moves it into NetBootstrap, so the moved-from local's own
+        // destructor runs stop() right after. An unconditional
+        // activeListenFd().store(-1) here used to stomp the atomic the
+        // moved-to (real, running) instance had just inherited, making
+        // acceptLoopTask() spin on accept(-1, ...) == EBADF forever from
+        // the very first boot -- root cause of the 2026-08-25 field
+        // observation, not a Wi-Fi-layer event.
+        int expected = listenFd_;
+        activeListenFd().compare_exchange_strong(expected, -1,
+                                                 std::memory_order_acq_rel);
         close(listenFd_);
         listenFd_ = -1;
     }
@@ -547,6 +558,59 @@ std::expected<void, NetError> SigmaStudioTcpServer::start()
     return {};
 }
 
+namespace {
+
+/**
+ * @brief    recreateListenSocket — rebind a fresh listening socket on kPort.
+ *
+ * @dname    recreateListenSocket
+ * @return   The new fd on success (also stored in activeListenFd()), or -1.
+ * @pubstate closes the previous fd read from activeListenFd() if any, then
+ *          publishes the new one.
+ *
+ * Self-healing counterpart to SigmaStudioTcpServer::start()'s socket setup.
+ * The 2026-08-25 field observation (accept() spinning on errno=EBADF
+ * forever) turned out to be a stop() lifetime bug, now fixed there: this
+ * function is kept as a safety net in case the singleton is ever cleared
+ * from underneath a running accept task by some future code path, not
+ * because it is expected to fire in normal operation.
+ */
+[[nodiscard]] int recreateListenSocket() noexcept
+{
+    const int oldFd = activeListenFd().exchange(-1, std::memory_order_acq_rel);
+    if (oldFd >= 0) {
+        close(oldFd);
+    }
+
+    const int fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
+    if (fd < 0) {
+        ESP_LOGE(kTag, "recreateListenSocket: socket() failed");
+        return -1;
+    }
+
+    const int reuse = 1;
+    setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &reuse, sizeof(reuse));
+
+    sockaddr_in addr{};
+    addr.sin_family = AF_INET;
+    addr.sin_addr.s_addr = htonl(INADDR_ANY);
+    addr.sin_port = htons(kPort);
+
+    if (bind(fd, reinterpret_cast<sockaddr*>(&addr), sizeof(addr)) != 0
+        || listen(fd, 1) != 0) {
+        ESP_LOGE(kTag, "recreateListenSocket: bind/listen failed, errno=%d",
+                errno);
+        close(fd);
+        return -1;
+    }
+
+    activeListenFd().store(fd, std::memory_order_release);
+    ESP_LOGW(kTag, "SigmaStudio TCP listen socket recreated after failure");
+    return fd;
+}
+
+} // namespace
+
 void SigmaStudioTcpServer::acceptLoopTask(void* /*arg*/)
 {
     while (true) {
@@ -556,8 +620,21 @@ void SigmaStudioTcpServer::acceptLoopTask(void* /*arg*/)
         const int clientFd = accept(
             listenFd, reinterpret_cast<sockaddr*>(&clientAddr), &clientLen);
         if (clientFd < 0) {
-            ESP_LOGW(kTag, "accept() failed: errno=%d", errno);
-            vTaskDelay(pdMS_TO_TICKS(100));
+            // EBADF means the listen socket itself is gone -- retrying
+            // accept() on the same fd forever can never recover from this,
+            // unlike a transient per-call error, so rebuild the socket
+            // instead of just backing off and looping.
+            if (errno == EBADF) {
+                ESP_LOGE(kTag,
+                        "accept() failed: listen socket invalid (errno=%d) "
+                        "-- recreating",
+                        errno);
+                (void)recreateListenSocket();
+                vTaskDelay(pdMS_TO_TICKS(500));
+            } else {
+                ESP_LOGW(kTag, "accept() failed: errno=%d", errno);
+                vTaskDelay(pdMS_TO_TICKS(100));
+            }
             continue;
         }
         ESP_LOGI(kTag, "SigmaStudio client connected");