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Commit e53e597f authored by Timur Tabi's avatar Timur Tabi Committed by Greg Kroah-Hartman
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tty: pl011: fix earlycon work-around for QDF2400 erratum 44 



The work-around for the Qualcomm Datacenter Technologies QDF2400
erratum 44 sets the "qdf2400_e44_present" global variable if the
work-around is needed.  However, this check does not happen until after
earlycon is initialized, which means the work-around is not
used, and the console hangs as soon as it displays one character.

Fixes: d8a4995b ("tty: pl011: Work around QDF2400 E44 stuck BUSY bit")
Signed-off-by: default avatarTimur Tabi <timur@codeaurora.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 49e1590c

drivers/tty/serial/amba-pl011.c

+21 −2
Original line number Diff line number Diff line
@@ -2452,18 +2452,37 @@ static void pl011_early_write(struct console *con, const char *s, unsigned n) 
	uart_console_write(&dev->port, s, n, pl011_putc);

}



/*

 * On non-ACPI systems, earlycon is enabled by specifying

 * "earlycon=pl011,<address>" on the kernel command line.

 *

 * On ACPI ARM64 systems, an "early" console is enabled via the SPCR table,

 * by specifying only "earlycon" on the command line.  Because it requires

 * SPCR, the console starts after ACPI is parsed, which is later than a

 * traditional early console.

 *

 * To get the traditional early console that starts before ACPI is parsed,

 * specify the full "earlycon=pl011,<address>" option.

 */

static int __init pl011_early_console_setup(struct earlycon_device *device,

					    const char *opt)

{

	if (!device->port.membase)

		return -ENODEV;



	device->con->write = qdf2400_e44_present ?

				qdf2400_e44_early_write : pl011_early_write;

	/* On QDF2400 SOCs affected by Erratum 44, the "qdf2400_e44" must

	 * also be specified, e.g. "earlycon=pl011,<address>,qdf2400_e44".

	 */

	if (!strcmp(device->options, "qdf2400_e44"))

		device->con->write = qdf2400_e44_early_write;

	else

		device->con->write = pl011_early_write;



	return 0;

}

OF_EARLYCON_DECLARE(pl011, "arm,pl011", pl011_early_console_setup);

OF_EARLYCON_DECLARE(pl011, "arm,sbsa-uart", pl011_early_console_setup);

EARLYCON_DECLARE(qdf2400_e44, pl011_early_console_setup);



#else

#define AMBA_CONSOLE	NULL