Messages in this thread Patch in this message | | | From | Andy Shevchenko <> | Subject | [PATCH v1 3/3] serial: 8250_port: Disable DMA operations for kernel console | Date | Tue, 15 May 2018 21:34:09 +0300 |
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It will be too tricky and error prone to allow DMA operations on kernel console.
Disable any kind of DMA operations in such case.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> --- drivers/tty/serial/8250/8250_port.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c index db97222a1bf4..9a4696ea728b 100644 --- a/drivers/tty/serial/8250/8250_port.c +++ b/drivers/tty/serial/8250/8250_port.c @@ -2371,7 +2371,10 @@ int serial8250_do_startup(struct uart_port *port) * Request DMA channels for both RX and TX. */ if (up->dma) { - retval = serial8250_request_dma(up); + if (uart_console(port)) + retval = -ENXIO; + else + retval = serial8250_request_dma(up); if (retval) pr_warn_ratelimited("ttyS%d - failed to request DMA\n", serial_index(port)); -- 2.17.0
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