From: Ronald Wahl Date: Wed, 1 Nov 2023 17:14:31 +0000 (+0100) Subject: serial: 8250: 8250_omap: Do not start RX DMA on THRI interrupt X-Git-Tag: v6.7-rc5~8^2~6 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=c6bb057418876cdfdd29a6f7b8cef54539ee8811;p=thirdparty%2Fkernel%2Flinux.git serial: 8250: 8250_omap: Do not start RX DMA on THRI interrupt Starting RX DMA on THRI interrupt is too early because TX may not have finished yet. This change is inspired by commit 90b8596ac460 ("serial: 8250: Prevent starting up DMA Rx on THRI interrupt") and fixes DMA issues I had with an AM62 SoC that is using the 8250 OMAP variant. Cc: stable@vger.kernel.org Fixes: c26389f998a8 ("serial: 8250: 8250_omap: Add DMA support for UARTs on K3 SoCs") Signed-off-by: Ronald Wahl Reviewed-by: Vignesh Raghavendra Link: https://lore.kernel.org/r/20231101171431.16495-1-rwahl@gmx.de Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c index 2d42f485c9876..7d99bc3be0b83 100644 --- a/drivers/tty/serial/8250/8250_omap.c +++ b/drivers/tty/serial/8250/8250_omap.c @@ -1298,10 +1298,12 @@ static int omap_8250_dma_handle_irq(struct uart_port *port) status = serial_port_in(port, UART_LSR); - if (priv->habit & UART_HAS_EFR2) - am654_8250_handle_rx_dma(up, iir, status); - else - status = omap_8250_handle_rx_dma(up, iir, status); + if ((iir & 0x3f) != UART_IIR_THRI) { + if (priv->habit & UART_HAS_EFR2) + am654_8250_handle_rx_dma(up, iir, status); + else + status = omap_8250_handle_rx_dma(up, iir, status); + } serial8250_modem_status(up); if (status & UART_LSR_THRE && up->dma->tx_err) {