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@@ -0,0 +1,45 @@
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+From 814453adea7d081ad8917aa0f32d6a14165a3563 Mon Sep 17 00:00:00 2001
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+From: Michal Simek <[email protected]>
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+Date: Tue, 10 Apr 2018 15:32:28 +0200
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+Subject: earlycon: Initialize port->uartclk based on clock-frequency property
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+
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+From: Michal Simek <[email protected]>
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+
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+commit 814453adea7d081ad8917aa0f32d6a14165a3563 upstream.
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+
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+On DT based platforms when current-speed property is present baudrate
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+is setup. Also port->uartclk is initialized to bogus BASE_BAUD * 16
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+value. Drivers like uartps/ns16550 contain logic when baudrate and
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+uartclk is used for baudrate calculation.
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+
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+The patch is reading optional clock-frequency property to replace bogus
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+BASE_BAUD * 16 calculation to have proper baudrate calculation.
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+
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+[-stable comment: commit 31cb9a8575ca ("earlycon: initialise baud field
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+ of earlycon device structure") has changed 8250_early.c behavior which
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+ now tries to setup UART speed. Ignoring clock-frequency results in
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+ wrong value of calculated divisor & malformed early console output.]
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+
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+Fixes: 31cb9a8575ca ("earlycon: initialise baud field of earlycon device structure")
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+Signed-off-by: Michal Simek <[email protected]>
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+[rmilecki: add -stable comment and Fixes tag]
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+Signed-off-by: Rafał Miłecki <[email protected]>
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+Signed-off-by: Greg Kroah-Hartman <[email protected]>
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+
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+---
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+ drivers/tty/serial/earlycon.c | 4 ++++
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+ 1 file changed, 4 insertions(+)
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+
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+--- a/drivers/tty/serial/earlycon.c
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++++ b/drivers/tty/serial/earlycon.c
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+@@ -289,6 +289,10 @@ int __init of_setup_earlycon(const struc
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+ if (val)
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+ early_console_dev.baud = be32_to_cpu(*val);
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+
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++ val = of_get_flat_dt_prop(node, "clock-frequency", NULL);
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++ if (val)
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++ port->uartclk = be32_to_cpu(*val);
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++
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+ if (options) {
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+ early_console_dev.baud = simple_strtoul(options, NULL, 0);
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+ strlcpy(early_console_dev.options, options,
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