Commit 26b29a6c authored by George G. Davis's avatar George G. Davis Committed by Greg Kroah-Hartman

serial: sh-sci: disable DMA for uart_console

commit 099506cb upstream.

As noted in commit 84b40e3b ("serial: 8250: omap: Disable DMA for
console UART"), UART console lines use low-level PIO only access functions
which will conflict with use of the line when DMA is enabled, e.g. when
the console line is also used for systemd messages. So disable DMA
support for UART console lines.
Reported-by: default avatarMichael Rodin <mrodin@de.adit-jv.com>
Link: https://patchwork.kernel.org/patch/10929511/Tested-by: default avatarEugeniu Rosca <erosca@de.adit-jv.com>
Reviewed-by: default avatarSimon Horman <horms+renesas@verge.net.au>
Reviewed-by: default avatarWolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: default avatarGeert Uytterhoeven <geert+renesas@glider.be>
Cc: stable@vger.kernel.org
Signed-off-by: default avatarGeorge G. Davis <george_davis@mentor.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 863f40c7
...@@ -1557,6 +1557,13 @@ static void sci_request_dma(struct uart_port *port) ...@@ -1557,6 +1557,13 @@ static void sci_request_dma(struct uart_port *port)
dev_dbg(port->dev, "%s: port %d\n", __func__, port->line); dev_dbg(port->dev, "%s: port %d\n", __func__, port->line);
/*
* DMA on console may interfere with Kernel log messages which use
* plain putchar(). So, simply don't use it with a console.
*/
if (uart_console(port))
return;
if (!port->dev->of_node) if (!port->dev->of_node)
return; return;
......
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