Author: jhb Date: Mon Apr 13 20:59:09 2020 New Revision: 359900 URL: https://svnweb.freebsd.org/changeset/base/359900
Log: Export a sysctl count of RX FIFO overrun events. uart(4) backends currently detect RX FIFO overrun errors and report them to the uart(4) core layer. They are then reported to the generic TTY layer which promptly ignores them. As a result, there is currently no good way to determine if a uart is experiencing RX FIFO overruns. One could add a generic per-tty counter, but there did not appear to be a good way to export those. Instead, add a sysctl under the uart(4) sysctl tree to export the count of overruns. Reviewed by: brooks MFC after: 2 weeks Sponsored by: DARPA Differential Revision: https://reviews.freebsd.org/D24368 Modified: head/sys/dev/uart/uart_bus.h head/sys/dev/uart/uart_core.c Modified: head/sys/dev/uart/uart_bus.h ============================================================================== --- head/sys/dev/uart/uart_bus.h Mon Apr 13 20:43:57 2020 (r359899) +++ head/sys/dev/uart/uart_bus.h Mon Apr 13 20:59:09 2020 (r359900) @@ -111,6 +111,7 @@ struct uart_softc { int sc_rxput; int sc_rxget; int sc_rxfifosz; /* Size of RX FIFO. */ + int sc_rxoverruns; /* Transmitter data. */ uint8_t *sc_txbuf; Modified: head/sys/dev/uart/uart_core.c ============================================================================== --- head/sys/dev/uart/uart_core.c Mon Apr 13 20:43:57 2020 (r359899) +++ head/sys/dev/uart/uart_core.c Mon Apr 13 20:59:09 2020 (r359900) @@ -333,6 +333,7 @@ uart_intr_overrun(void *arg) sc->sc_rxbuf[sc->sc_rxput] = UART_STAT_OVERRUN; uart_sched_softih(sc, SER_INT_RXREADY); } + sc->sc_rxoverruns++; UART_FLUSH(sc, UART_FLUSH_RECEIVER); return (0); } @@ -740,6 +741,12 @@ uart_bus_attach(device_t dev) if (sc->sc_sysdev != NULL) sc->sc_sysdev->hwmtx = sc->sc_hwmtx; + + if (sc->sc_rxfifosz > 1) + SYSCTL_ADD_INT(device_get_sysctl_ctx(dev), + SYSCTL_CHILDREN(device_get_sysctl_tree(dev)), OID_AUTO, + "rx_overruns", CTLFLAG_RD, &sc->sc_rxoverruns, 0, + "Receive overruns"); return (0); _______________________________________________ [email protected] mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "[email protected]"
