From: Shenwei Wang Date: Mon, 10 Apr 2023 19:55:55 +0000 (-0500) Subject: tty: serial: fsl_lpuart: adjust buffer length to the intended size X-Git-Tag: v6.2.15~169 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8a06d7ad7144097d959e8556e1d1648c8e57d720;p=thirdparty%2Fkernel%2Fstable.git tty: serial: fsl_lpuart: adjust buffer length to the intended size [ 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 Link: https://lore.kernel.org/r/20230410195555.1003900-1-shenwei.wang@nxp.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- 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;