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tty: serial: fsl_lpuart: move dma_request_chan() 

Move dma_request_chan() out of the atomic context. First this call
should not be in the atomic context at all and second the
dev_info_once() may cause a hang because because the console takes this
spinlock, too.

Fixes: 159381df14 ("tty: serial: fsl_lpuart: fix DMA operation when using IOMMU")
Reported-by: Leonard Crestez <leonard.crestez@nxp.com>
Signed-off-by: Michael Walle <michael@walle.cc>
Reviewed-by: Fugang Duan <fugang.duan@nxp.com>
Tested-by: Leonard Crestez <leonard.crestez@nxp.com>
Link: https://lore.kernel.org/r/20200325090658.25967-1-michael@walle.cc
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Michael Walle 2020-03-25 10:06:57 +01:00 committed by Greg Kroah-Hartman
parent a0c4adeeea
commit d0e7600b91
1 changed files with 23 additions and 13 deletions
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36
drivers/tty/serial/fsl_lpuart.c
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@ -1510,20 +1510,33 @@ static void rx_dma_timer_init(struct lpuart_port *sport)
add_timer(&sport->lpuart_timer);
}
static void lpuart_tx_dma_startup(struct lpuart_port *sport)
static void lpuart_request_dma(struct lpuart_port *sport)
{
u32 uartbaud;
int ret;
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;
}
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;
}
}
static void lpuart_tx_dma_startup(struct lpuart_port *sport)
{
u32 uartbaud;
int ret;
if (!sport->dma_tx_chan)
goto err;
ret = lpuart_dma_tx_request(&sport->port);
if (!ret)
goto err;
@ -1549,14 +1562,8 @@ static void lpuart_rx_dma_startup(struct lpuart_port *sport)
{
int ret;
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;
if (!sport->dma_rx_chan)
goto err;
}
ret = lpuart_start_rx_dma(sport);
if (ret)
@ -1592,6 +1599,8 @@ static int lpuart_startup(struct uart_port *port)
sport->rxfifo_size = UARTFIFO_DEPTH((temp >> UARTPFIFO_RXSIZE_OFF) &
UARTPFIFO_FIFOSIZE_MASK);
lpuart_request_dma(sport);
spin_lock_irqsave(&sport->port.lock, flags);
lpuart_setup_watermark_enable(sport);
@ -1649,11 +1658,12 @@ static int lpuart32_startup(struct uart_port *port)
sport->port.fifosize = sport->txfifo_size;
}
lpuart_request_dma(sport);
spin_lock_irqsave(&sport->port.lock, flags);
lpuart32_setup_watermark_enable(sport);
lpuart_rx_dma_startup(sport);
lpuart_tx_dma_startup(sport);