From: Shenwei Wang shenwei.wang@nxp.com
[ Upstream commit f73fd750552524b06b5d77ebfdd106ccc8fcac61 ]
Based on the fls function definition provided below, we should not subtract 1 to obtain the correct buffer length:
fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
Fixes: 5887ad43ee02 ("tty: serial: fsl_lpuart: Use cyclic DMA for Rx") Signed-off-by: Shenwei Wang shenwei.wang@nxp.com Link: https://lore.kernel.org/r/20230410195555.1003900-1-shenwei.wang@nxp.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/tty/serial/fsl_lpuart.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c index 59c10bceebbef..29b50a0792dcf 100644 --- a/drivers/tty/serial/fsl_lpuart.c +++ b/drivers/tty/serial/fsl_lpuart.c @@ -1270,7 +1270,7 @@ static inline int lpuart_start_rx_dma(struct lpuart_port *sport) * 10ms at any baud rate. */ sport->rx_dma_rng_buf_len = (DMA_RX_TIMEOUT * baud / bits / 1000) * 2; - sport->rx_dma_rng_buf_len = (1 << (fls(sport->rx_dma_rng_buf_len) - 1)); + sport->rx_dma_rng_buf_len = (1 << fls(sport->rx_dma_rng_buf_len)); if (sport->rx_dma_rng_buf_len < 16) sport->rx_dma_rng_buf_len = 16;