From 6b4424efcfaa64929ec158dff1a86d6fcee2c046 Mon Sep 17 00:00:00 2001 From: Kartik Date: Tue, 18 Oct 2022 20:28:06 +0530 Subject: [PATCH] serial: tegra: Read DMA status before terminating MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit [ Upstream commit 109a951a9f1fd8a34ebd1896cbbd5d5cede880a7 ] Read the DMA status before terminating the DMA, as doing so deletes the DMA desc. Also, to get the correct transfer status information, pause the DMA using dmaengine_pause() before reading the DMA status. Fixes: e9ea096dd225 ("serial: tegra: add serial driver") Reviewed-by: Jon Hunter Reviewed-by: Ilpo Järvinen Acked-by: Thierry Reding Signed-off-by: Akhil R Signed-off-by: Kartik Link: https://lore.kernel.org/r/1666105086-17326-1-git-send-email-kkartik@nvidia.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/tty/serial/serial-tegra.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/tty/serial/serial-tegra.c b/drivers/tty/serial/serial-tegra.c index d4dba298de7a..79187ff9ac13 100644 --- a/drivers/tty/serial/serial-tegra.c +++ b/drivers/tty/serial/serial-tegra.c @@ -619,8 +619,9 @@ static void tegra_uart_stop_tx(struct uart_port *u) if (tup->tx_in_progress != TEGRA_UART_TX_DMA) return; - dmaengine_terminate_all(tup->tx_dma_chan); + dmaengine_pause(tup->tx_dma_chan); dmaengine_tx_status(tup->tx_dma_chan, tup->tx_cookie, &state); + dmaengine_terminate_all(tup->tx_dma_chan); count = tup->tx_bytes_requested - state.residue; async_tx_ack(tup->tx_dma_desc); uart_xmit_advance(&tup->uport, count); @@ -763,8 +764,9 @@ static void tegra_uart_terminate_rx_dma(struct tegra_uart_port *tup) return; } - dmaengine_terminate_all(tup->rx_dma_chan); + dmaengine_pause(tup->rx_dma_chan); dmaengine_tx_status(tup->rx_dma_chan, tup->rx_cookie, &state); + dmaengine_terminate_all(tup->rx_dma_chan); tegra_uart_rx_buffer_push(tup, state.residue); tup->rx_dma_active = false;