From: Ilpo Järvinen ilpo.jarvinen@linux.intel.com
stable inclusion from stable-v5.10.146 commit e1993864a935cb2e0472f23a72f9cc7212f316ec category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I6D0VX
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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commit 754f68044c7dd6c52534ba3e0f664830285c4b15 upstream.
DMA complete & stop paths did not correctly account Tx'ed characters into icount.tx. Using uart_xmit_advance() fixes the problem.
Fixes: e9ea096dd225 ("serial: tegra: add serial driver") Cc: stable@vger.kernel.org # serial: Create uart_xmit_advance() Reviewed-by: Andy Shevchenko andy.shevchenko@gmail.com Signed-off-by: Ilpo Järvinen ilpo.jarvinen@linux.intel.com Link: https://lore.kernel.org/r/20220901143934.8850-3-ilpo.jarvinen@linux.intel.co... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Jialin Zhang zhangjialin11@huawei.com Reviewed-by: Zheng Zengkai zhengzengkai@huawei.com --- drivers/tty/serial/serial-tegra.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/drivers/tty/serial/serial-tegra.c b/drivers/tty/serial/serial-tegra.c index c2be22c3b7d1..cda71802b698 100644 --- a/drivers/tty/serial/serial-tegra.c +++ b/drivers/tty/serial/serial-tegra.c @@ -520,7 +520,7 @@ static void tegra_uart_tx_dma_complete(void *args) count = tup->tx_bytes_requested - state.residue; async_tx_ack(tup->tx_dma_desc); spin_lock_irqsave(&tup->uport.lock, flags); - xmit->tail = (xmit->tail + count) & (UART_XMIT_SIZE - 1); + uart_xmit_advance(&tup->uport, count); tup->tx_in_progress = 0; if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) uart_write_wakeup(&tup->uport); @@ -608,7 +608,6 @@ static unsigned int tegra_uart_tx_empty(struct uart_port *u) static void tegra_uart_stop_tx(struct uart_port *u) { struct tegra_uart_port *tup = to_tegra_uport(u); - struct circ_buf *xmit = &tup->uport.state->xmit; struct dma_tx_state state; unsigned int count;
@@ -619,7 +618,7 @@ static void tegra_uart_stop_tx(struct uart_port *u) dmaengine_tx_status(tup->tx_dma_chan, tup->tx_cookie, &state); count = tup->tx_bytes_requested - state.residue; async_tx_ack(tup->tx_dma_desc); - xmit->tail = (xmit->tail + count) & (UART_XMIT_SIZE - 1); + uart_xmit_advance(&tup->uport, count); tup->tx_in_progress = 0; }