[PATCH-tty-testing] tty/serial/8250: Add has_sysrq to plat_serial8250_port

[Dmitry Safonov <dima@arista.com>]

In contrast to 8250/8250_of, legacy_serial on powerpc does fill
(struct plat_serial8250_port). The reason is likely that it's done on
device_initcall(), not on probe. So, 8250_core is not yet probed.

Propagate value from platform_device on 8250 probe - in case powepc
legacy driver it's initialized on initcall, in case 8250_of it will be
initialized later on of_platform_serial_setup().

Fixes: ea2683bf546c ("tty/serial: Migrate 8250_fsl to use has_sysrq").
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
---
 It's probably better to squash this into the 8250_fsl patch.
 I've added Fixes tag in case the branch won't be rebased.
 Tested powerpc build manually with ppc64 cross-compiler.

 drivers/tty/serial/8250/8250_core.c | 1 +
 include/linux/serial_8250.h         | 1 +
 2 files changed, 2 insertions(+)

diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c
index e682390ce0de..0894a22fd702 100644
--- a/drivers/tty/serial/8250/8250_core.c
+++ b/drivers/tty/serial/8250/8250_core.c
@@ -816,6 +816,7 @@ static int serial8250_probe(struct platform_device *dev)
 		uart.port.flags		= p->flags;
 		uart.port.mapbase	= p->mapbase;
 		uart.port.hub6		= p->hub6;
+		uart.port.has_sysrq	= p->has_sysrq;
 		uart.port.private_data	= p->private_data;
 		uart.port.type		= p->type;
 		uart.port.serial_in	= p->serial_in;
diff --git a/include/linux/serial_8250.h b/include/linux/serial_8250.h
index bb2bc99388ca..6a8e8c48c882 100644
--- a/include/linux/serial_8250.h
+++ b/include/linux/serial_8250.h
@@ -25,6 +25,7 @@ struct plat_serial8250_port {
 	unsigned char	regshift;	/* register shift */
 	unsigned char	iotype;		/* UPIO_* */
 	unsigned char	hub6;
+	unsigned char	has_sysrq;	/* supports magic SysRq */
 	upf_t		flags;		/* UPF_* flags */
 	unsigned int	type;		/* If UPF_FIXED_TYPE */
 	unsigned int	(*serial_in)(struct uart_port *, int);
-- 
2.24.1