From b1fdf753387189afe720d3fa1ac13af5fb9943c2 Mon Sep 17 00:00:00 2001 From: Adrien Chardon Date: Wed, 24 Jan 2024 18:01:52 +0100 Subject: bsp/tms570: Fix console receive interrupts `tms570_sci_interrupt_handler()` is called when an RX interrupt fires. It checks in the register `FLR`, the `RXRDY` bit (Receiver ready flag - indicate that the SCIRD contains new data). If it is set, it calls `tms570_sci_read_received_chars()`. `tms570_sci_read_received_chars()` checks the register `RD` against 0. If it is non zero, it returns 1 to indicate that one byte was read. In the old behavior, if it is zero, the function returns 0 to indicate that no data was read. The new behavior is to not silently drop 0x00 bytes. Ignoring 0x00 bytes is fine when working with printable text (which, I assume, is how this driver was tested), but as soon as the UART is used in non canonical (raw) mode, with potentially 0x00 bytes, these bytes will be silently dropped, causing issues in the data/protocol layer above. Update #4982. --- bsps/arm/tms570/console/tms570-sci.c | 45 ++++++++---------------------------- 1 file changed, 9 insertions(+), 36 deletions(-) (limited to 'bsps') diff --git a/bsps/arm/tms570/console/tms570-sci.c b/bsps/arm/tms570/console/tms570-sci.c index b945855986..63f8e7c8ee 100644 --- a/bsps/arm/tms570/console/tms570-sci.c +++ b/bsps/arm/tms570/console/tms570-sci.c @@ -49,8 +49,6 @@ #include #include -#define TMS570_SCI_BUFFER_SIZE 1 - /** * @brief Table including all serial drivers * @@ -171,33 +169,6 @@ rtems_device_driver console_initialize( return RTEMS_SUCCESSFUL; } -/** - * @brief Reads chars from HW - * - * Reads chars from HW peripheral specified in driver context. - * TMS570 does not have HW buffer for serial line so this function can - * return only 0 or 1 char - * - * @param[in] ctx context of the driver - * @param[out] buf read data buffer - * @param[in] N size of buffer - * @retval x Number of read chars from peripherals - */ -static int tms570_sci_read_received_chars( - tms570_sci_context * ctx, - char * buf, - int N) -{ - if ( N < 1 ) { - return 0; - } - if ( ctx->regs->RD != 0 ) { - buf[0] = ctx->regs->RD; - return 1; - } - return 0; -} - /** * @brief Enables RX interrupt * @@ -351,23 +322,25 @@ static void tms570_sci_interrupt_handler(void * arg) { rtems_termios_tty *tty = arg; tms570_sci_context *ctx = rtems_termios_get_device_context(tty); - char buf[TMS570_SCI_BUFFER_SIZE]; - size_t n; /* * Check if we have received something. */ if ( (ctx->regs->FLR & TMS570_SCI_FLR_RXRDY ) == TMS570_SCI_FLR_RXRDY ) { - n = tms570_sci_read_received_chars(ctx, buf, TMS570_SCI_BUFFER_SIZE); - if ( n > 0 ) { - /* Hand the data over to the Termios infrastructure */ - rtems_termios_enqueue_raw_characters(tty, buf, n); - } + char buf[1]; + + /* Read the received byte */ + buf[0] = ctx->regs->RD & 0x000000FF; + + /* Hand the data over to the Termios infrastructure */ + rtems_termios_enqueue_raw_characters(tty, buf, 1); } /* * Check if we have something transmitted. */ if ( (ctx->regs->FLR & TMS570_SCI_FLR_TXRDY ) == TMS570_SCI_FLR_TXRDY ) { + size_t n; + n = tms570_sci_transmitted_chars(ctx); if ( n > 0 ) { /* -- cgit v1.2.3