[3.19.y-ckt stable] Patch "serial: of-serial: Remove device_type = "serial" registration" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    serial: of-serial: Remove device_type = "serial" registration

to the linux-3.19.y-queue branch of the 3.19.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.19.y-queue

This patch is scheduled to be released in version 3.19.8-ckt1.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.19.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 36a0b8d7c16150287305d08b4fa5f6af0dcc4a68 Mon Sep 17 00:00:00 2001
From: Michal Simek <michal.simek at xilinx.com>
Date: Tue, 14 Apr 2015 12:03:09 +0200
Subject: serial: of-serial: Remove device_type = "serial" registration

commit 6befa9d883385c580369a2cc9e53fbf329771f6d upstream.

Do not probe all serial drivers by of_serial.c which are using
device_type = "serial"; property. Only drivers which have valid
compatible strings listed in the driver should be probed.

When PORT_UNKNOWN is setup probe will fail anyway.

Arnd quotation about driver historical background:
"when I wrote that driver initially, the idea was that it would
get used as a stub to hook up all other serial drivers but after
that, the common code learned to create platform devices from DT"

This patch fix the problem with on the system with xilinx_uartps and
16550a where of_serial failed to register for xilinx_uartps and because
of irq_dispose_mapping() removed irq_desc. Then when xilinx_uartps was asking
for irq with request_irq() EINVAL is returned.

Signed-off-by: Michal Simek <michal.simek at xilinx.com>
Acked-by: Arnd Bergmann <arnd at arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/tty/serial/of_serial.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/tty/serial/of_serial.c b/drivers/tty/serial/of_serial.c
index 64f1bab..e79d884 100644
--- a/drivers/tty/serial/of_serial.c
+++ b/drivers/tty/serial/of_serial.c
@@ -335,7 +335,6 @@ static struct of_device_id of_platform_serial_table[] = {
 	{ .compatible = "ibm,qpace-nwp-serial",
 		.data = (void *)PORT_NWPSERIAL, },
 #endif
-	{ .type = "serial",         .data = (void *)PORT_UNKNOWN, },
 	{ /* end of list */ },
 };

--
1.9.1