This is a note to let you know that I've just added the patch titled serial: tegra: Read DMA status before terminating to the 5.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: serial-tegra-read-dma-status-before-terminating.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit b42edab3b327c3c8d00278fdd8b5ac7f52324bef Author: Kartik <kkartik@xxxxxxxxxx> Date: Tue Oct 18 20:28:06 2022 +0530 serial: tegra: Read DMA status before terminating [ 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 <jonathanh@xxxxxxxxxx> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx> Acked-by: Thierry Reding <treding@xxxxxxxxxx> Signed-off-by: Akhil R <akhilrajeev@xxxxxxxxxx> Signed-off-by: Kartik <kkartik@xxxxxxxxxx> Link: https://lore.kernel.org/r/1666105086-17326-1-git-send-email-kkartik@xxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> 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;