From 88c8623cedbdc5a2d7cee82cec33fa265271b8e1 Mon Sep 17 00:00:00 2001 From: Felipe Moura Date: Tue, 15 Sep 2026 15:26:02 -0300 Subject: [PATCH] xtensa/espressif: enable openeth RX interrupt, fix ifdown()'s TX/RX disable esp_openeth_initialize() (arch/xtensa/src/common/espressif/esp_openeth.c) attaches the MAC interrupt with esp_setup_irq() but never calls up_enable_irq(OPENETH_IRQ_MAC), unlike every other Espressif driver in this tree. Left masked, openeth_isr_handler() never runs and received frames are only picked up when the netdev work thread happens to run for some other reason (a transmit). A guest can therefore send but effectively not receive: ping still works because each request is itself a transmit, while a socket blocked in recvfrom() waits on a wake-up that never comes. Confirmed with a GDB breakpoint counter on openeth_isr_handler(): zero hits before the fix, dozens after, under QEMU's esp32s3 machine (the open_eth NIC it emulates). With the interrupt enabled, TCP retransmits over a fixed test window dropped from 86 to 4. Separately, openeth_ifdown() calls openeth_enable() right under a comment that says "Disable TX and RX" -- it should call openeth_disable(), which is what actually disables the two DMA descriptor rings. Fixed alongside since it's the same function and the same class of mistake. Board-independent (arch/xtensa/src/common/espressif), not specific to any one esp32s3 board; open_eth itself only exists as a QEMU peripheral, so there's no real-hardware regression risk from either change. Signed-off-by: Felipe Moura Assisted-by: Claude:claude-sonnet-5 --- arch/xtensa/src/common/espressif/esp_openeth.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/arch/xtensa/src/common/espressif/esp_openeth.c b/arch/xtensa/src/common/espressif/esp_openeth.c index 1376ede0993..ed58e7ed357 100644 --- a/arch/xtensa/src/common/espressif/esp_openeth.c +++ b/arch/xtensa/src/common/espressif/esp_openeth.c @@ -366,7 +366,7 @@ static int openeth_ifdown(struct netdev_lowerhalf_s *dev) /* Disable TX and RX */ - openeth_enable(); + openeth_disable(); leave_critical_section(flags); @@ -424,6 +424,7 @@ static int openeth_set_addr(uint8_t *addr) uint32_t mac0_u32; uint32_t mac1_u32; + memcpy(&mac0_u32, &mac0, 4); memcpy(&mac1_u32, &mac1, 4); REG_WRITE(OPENETH_MAC_ADDR0_REG, mac0_u32); @@ -524,6 +525,12 @@ int esp_openeth_initialize(void) goto err; } + /* The interrupt is attached but still masked at the CPU; without this + * call it never fires, so received frames are only picked up on a TX. + */ + + up_enable_irq(OPENETH_IRQ_MAC); + /* Initialize the MAC */ openeth_reset();