Re: [PATCH 1/3] tty: serial: fsl_lpuart: move dev_info_once()
From: Michael Walle <hidden>
Date: 2020-03-25 09:15:13
Also in:
lkml
Am 2020-03-24 19:47, schrieb Michael Walle:
Don't take the spinlock and use dev_info_once(). This may cause a hang
because the console takes this spinlock, too. Just print this info
after
we've released the lock.
Fixes: 159381df1442f ("tty: serial: fsl_lpuart: fix DMA operation when
using IOMMU")
Reported-by: Leonard Crestez <redacted>
Signed-off-by: Michael Walle <redacted>Because the patch subject was renamed: This patch series is superseded by the v2: https://lore.kernel.org/linux-serial/20200325090658.25967-1-michael@walle.cc/ (local) I didn't include the 3/3 RFC patch though. This is a bigger change, which should be carefully reviewed by the maintainer of the fsl_lpuart.c. -michael
quoted hunk ↗ jump to hunk
--- drivers/tty/serial/fsl_lpuart.c | 22 +++++++++++++++------- 1 file changed, 15 insertions(+), 7 deletions(-)diff --git a/drivers/tty/serial/fsl_lpuart.cb/drivers/tty/serial/fsl_lpuart.c index 9c6a018b1390..960fc2658f19 100644--- a/drivers/tty/serial/fsl_lpuart.c +++ b/drivers/tty/serial/fsl_lpuart.c@@ -1517,9 +1517,6 @@ static void lpuart_tx_dma_startup(structlpuart_port *sport) sport->dma_tx_chan = dma_request_chan(sport->port.dev, "tx"); if (IS_ERR(sport->dma_tx_chan)) { - dev_info_once(sport->port.dev, - "DMA tx channel request failed, operating without tx DMA (%ld)\n", - PTR_ERR(sport->dma_tx_chan)); sport->dma_tx_chan = NULL; goto err; }@@ -1551,9 +1548,6 @@ static void lpuart_rx_dma_startup(structlpuart_port *sport) sport->dma_rx_chan = dma_request_chan(sport->port.dev, "rx"); if (IS_ERR(sport->dma_rx_chan)) { - dev_info_once(sport->port.dev, - "DMA rx channel request failed, operating without rx DMA (%ld)\n", - PTR_ERR(sport->dma_rx_chan)); sport->dma_rx_chan = NULL; goto err; }@@ -1601,6 +1595,13 @@ static int lpuart_startup(struct uart_port*port) spin_unlock_irqrestore(&sport->port.lock, flags); + if (!sport->dma_rx_chan) + dev_info_once(sport->port.dev, + "DMA rx channel request failed, operating without rx DMA\n"); + if (!sport->dma_tx_chan) + dev_info_once(sport->port.dev, + "DMA tx channel request failed, operating without tx DMA\n"); + return 0; }@@ -1653,13 +1654,20 @@ static int lpuart32_startup(struct uart_port*port) lpuart32_setup_watermark_enable(sport); - lpuart_rx_dma_startup(sport); lpuart_tx_dma_startup(sport); lpuart32_configure(sport); spin_unlock_irqrestore(&sport->port.lock, flags); + + if (!sport->dma_rx_chan) + dev_info_once(sport->port.dev, + "DMA rx channel request failed, operating without rx DMA\n"); + if (!sport->dma_tx_chan) + dev_info_once(sport->port.dev, + "DMA tx channel request failed, operating without tx DMA\n"); + return 0; }