Changeset 29f9822 in rtems-libbsd

Timestamp:

06/01/22 07:45:13 (19 months ago)

Author:

Sebastian Huber <sebastian.huber@…>

Branches:

5-freebsd-12

Children:

484186e

Parents:

62d320d

git-author:

Sebastian Huber <sebastian.huber@…> (06/01/22 07:45:13)

git-committer:

Sebastian Huber <sebastian.huber@…> (06/01/22 07:55:25)

Message:

if_atsam: Recover from receive freezes

Under unknown conditions the receive path ended up in a frozen state.
In this state, the DMA and driver descriptor head were equal and all
receive descriptors had the used bit set. So, the DMA was unable to
store received frames. However, the receive daemon was never woken up
to refill the receive buffers. It seems that the RXUBR interrupt can be
used to recover from this state.

Update #4651.

File:

• rtemsbsd/sys/dev/atsam/if_atsam.c (modified) (6 diffs)

rtemsbsd/sys/dev/atsam/if_atsam.c

@@ -109 +109 @@
 #define IGNORE_RX_ERR false
 
+#define RX_INTERRUPTS (GMAC_ISR_RCOMP | GMAC_ISR_RXUBR | GMAC_ISR_ROVR)
+
 #define RX_DESC_LOG2 3
 #define RX_DESC_COUNT (1U << RX_DESC_LOG2)
@@ -188 +190 @@
                 /* Software */
                 uint32_t rx_overrun_errors;
+                uint32_t rx_used_bit_reads;
                 uint32_t rx_interrupts;
                 uint32_t tx_tur_errors;
@@ -401 +404 @@
 
         /* Check receive interrupts */
-        if (__predict_true((is & (GMAC_IER_ROVR | GMAC_IER_RCOMP)) != 0)) {
-                if (__predict_false((is & GMAC_IER_ROVR) != 0)) {
+        if (__predict_true((is & RX_INTERRUPTS) != 0)) {
+                if (__predict_false((is & GMAC_ISR_RXUBR) != 0)) {
+                        ++sc->stats.rx_used_bit_reads;
+                }
+
+                if (__predict_false((is & GMAC_ISR_ROVR) != 0)) {
                         ++sc->stats.rx_overrun_errors;
                 }
@@ -408 +415 @@
                 ++sc->stats.rx_interrupts;
 
-                /* Erase the interrupts for RX completion and errors */
-                pHw->GMAC_IDR = GMAC_IER_RCOMP | GMAC_IER_ROVR;
+                /* Disable RX interrupts */
+                pHw->GMAC_IDR = RX_INTERRUPTS;
 
                 (void)rtems_event_send(sc->rx_daemon_tid,
@@ -512 +519 @@
 
                 /* Enable RX interrupts */
-                pHw->GMAC_IER = GMAC_IER_RCOMP | GMAC_IER_ROVR;
+                pHw->GMAC_IER = RX_INTERRUPTS;
 
                 (void) rtems_event_receive(ATSAMV7_ETH_RX_EVENT_INTERRUPT,
@@ -1293 +1300 @@
             CTLFLAG_RD, &sc->stats.rx_overrun_errors, 0,
             "RX overrun errors");
+        SYSCTL_ADD_UINT(ctx, child, OID_AUTO, "rx_used_bit_reads",
+            CTLFLAG_RD, &sc->stats.rx_used_bit_reads, 0,
+            "RX used bit reads");
         SYSCTL_ADD_UINT(ctx, child, OID_AUTO, "rx_interrupts",
             CTLFLAG_RD, &sc->stats.rx_interrupts, 0,