From 738c1161c07cb6e2cb1482124d287ad322415b99 Mon Sep 17 00:00:00 2001
From: Gunar Schorcht <gunar@schorcht.net>
Date: Fri, 4 May 2018 14:55:36 +0200
Subject: [PATCH] enc28j60: improvements to fix #9043
---
drivers/enc28j60/enc28j60.c | 58 ++++++++++++++++++++++++++++++++-----
drivers/include/enc28j60.h | 1 +
2 files changed, 52 insertions(+), 7 deletions(-)
diff --git a/drivers/enc28j60/enc28j60.c b/drivers/enc28j60/enc28j60.c
index 4471efe985..1ba6240d01 100644
--- a/drivers/enc28j60/enc28j60.c
+++ b/drivers/enc28j60/enc28j60.c
@@ -70,10 +70,18 @@
* RX must start at buffer address 0x0000 (see errata sheet, section 5)
*/
#define BUF_TX_START ((BUFFER_SIZE / 4) * 3)
-#define BUF_TX_END (BUFFER_SIZE - 2)
+#define BUF_TX_END (BUFFER_SIZE - 1)
#define BUF_RX_START (0)
-#define BUF_RX_END (BUF_TX_START - 2)
+#define BUF_RX_END (BUF_TX_START - 1)
+/**
+ * @brief Maximum transmission time
+ *
+ * The time in us that is required to send an Ethernet frame of maximum length
+ * (Preamle + SFD + 1518 byte) at 10 Mbps in full duplex mode with a guard
+ * period of 9,6 us. This time is used as time out for send operations.
+ */
+#define MAX_TX_TIME (1230U)
static void switch_bank(enc28j60_t *dev, int8_t bank)
{
@@ -248,6 +256,28 @@ static int nd_send(netdev_t *netdev, const iolist_t *iolist)
mutex_lock(&dev->devlock);
+ if (cmd_rcr(dev, REG_ECON1, -1) & ECON1_TXRTS) {
+ /* there is already a transmission in progress */
+ if (xtimer_now_usec() - dev->tx_time > MAX_TX_TIME * 2) {
+ /*
+ * if transmission time exceeds the double of maximum transmission
+ * time, we suppose that TX logic hangs and has to be reset
+ */
+ cmd_bfs(dev, REG_ECON1, -1, ECON1_TXRST);
+ cmd_bfc(dev, REG_ECON1, -1, ECON1_TXRST);
+ }
+ else {
+ /*
+ * otherwise we suppose that the transmission is still in progress
+ * and return EBUSY
+ */
+ mutex_unlock(&dev->devlock);
+ return -EBUSY;
+ }
+ }
+
+ /* set TX start pointer */
+ cmd_w_addr(dev, ADDR_TX_START, BUF_TX_START);
/* set write pointer */
cmd_w_addr(dev, ADDR_WRITE_PTR, BUF_TX_START);
/* write control byte and the actual data into the buffer */
@@ -260,6 +290,8 @@ static int nd_send(netdev_t *netdev, const iolist_t *iolist)
cmd_w_addr(dev, ADDR_TX_END, cmd_r_addr(dev, ADDR_WRITE_PTR) - 1);
/* trigger the send process */
cmd_bfs(dev, REG_ECON1, -1, ECON1_TXRTS);
+ /* set last transmission time for timeout handling */
+ dev->tx_time = xtimer_now_usec();
#ifdef MODULE_NETSTATS_L2
netdev->stats.tx_bytes += c;
@@ -269,23 +301,34 @@ static int nd_send(netdev_t *netdev, const iolist_t *iolist)
return c;
}
+/*
+ * Section 14 of errata sheet: Even values in ERXRDPT may corrupt receive
+ * buffer as well as the next packet pointer. ERXRDPT need to be set always
+ * at odd addresses. Following macros determine odd ERXRDPT from next packet
+ * pointer and vise versa. Next packet pointer is always at even address
+ * because of hardware padding.
+ */
+#define NEXT_TO_ERXRDPT(n) ((n == BUF_RX_START || n - 1 > BUF_RX_END) ? BUF_RX_END : n - 1)
+#define ERXRDPT_TO_NEXT(e) ((e >= BUF_RX_END) ? BUF_RX_START : e + 1)
+
static int nd_recv(netdev_t *netdev, void *buf, size_t max_len, void *info)
{
enc28j60_t *dev = (enc28j60_t *)netdev;
uint8_t head[6];
- size_t size;
+ uint16_t size;
uint16_t next;
(void)info;
mutex_lock(&dev->devlock);
/* set read pointer to RX read address */
- cmd_w_addr(dev, ADDR_READ_PTR, cmd_r_addr(dev, ADDR_RX_READ));
+ uint16_t rx_rd_ptr = cmd_r_addr(dev, ADDR_RX_READ);
+ cmd_w_addr(dev, ADDR_READ_PTR, ERXRDPT_TO_NEXT(rx_rd_ptr));
/* read packet header */
cmd_rbm(dev, head, 6);
/* TODO: care for endianess */
next = (uint16_t)((head[1] << 8) | head[0]);
- size = (size_t)((head[3] << 8) | head[2]) - 4; /* discard CRC */
+ size = (uint16_t)((head[3] << 8) | head[2]) - 4; /* discard CRC */
if (buf != NULL) {
#ifdef MODULE_NETSTATS_L2
@@ -300,7 +343,7 @@ static int nd_recv(netdev_t *netdev, void *buf, size_t max_len, void *info)
size = 0;
}
/* release memory */
- cmd_w_addr(dev, ADDR_RX_READ, next);
+ cmd_w_addr(dev, ADDR_RX_READ, NEXT_TO_ERXRDPT(next));
cmd_bfs(dev, REG_ECON2, -1, ECON2_PKTDEC);
}
@@ -348,7 +391,7 @@ static int nd_init(netdev_t *netdev)
/* configure the RX buffer */
cmd_w_addr(dev, ADDR_RX_START, BUF_RX_START);
cmd_w_addr(dev, ADDR_RX_END, BUF_RX_END);
- cmd_w_addr(dev, ADDR_RX_READ, BUF_RX_START);
+ cmd_w_addr(dev, ADDR_RX_READ, NEXT_TO_ERXRDPT(BUF_RX_START));
/* configure the TX buffer */
cmd_w_addr(dev, ADDR_TX_START, BUF_TX_START);
cmd_w_addr(dev, ADDR_TX_END, BUF_TX_END);
@@ -499,4 +542,5 @@ void enc28j60_setup(enc28j60_t *dev, const enc28j60_params_t *params)
dev->reset_pin = params->reset_pin;
mutex_init(&dev->devlock);
dev->bank = 99; /* mark as invalid */
+ dev->tx_time = 0;
}
diff --git a/drivers/include/enc28j60.h b/drivers/include/enc28j60.h
index 13427c09c8..6fd0bded37 100644
--- a/drivers/include/enc28j60.h
+++ b/drivers/include/enc28j60.h
@@ -53,6 +53,7 @@ typedef struct {
gpio_t reset_pin; /**< pin connected to the RESET line */
mutex_t devlock; /**< lock the device on access */
int8_t bank; /**< remember the active register bank */
+ uint32_t tx_time; /**< last transmission time for timeout handling */
} enc28j60_t;
/**
--
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