linux-arm-kernel.lists.infradead.org archive mirror
 help / color / mirror / Atom feed
From: khilman@linaro.org (Kevin Hilman)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] ARM: OMAP2+: omap_device: use late_initcall_sync
Date: Tue,  7 May 2013 14:39:25 -0700	[thread overview]
Message-ID: <1367962765-13912-1-git-send-email-khilman@linaro.org> (raw)

If DEBUG_LL and earlyprintk are enabled, and omap-serial.c is compiled
as a module, the kernel boot hangs early as the clocks for serial port
are cut while earlyprintk still uses the port.

The problem is a race between the late_initcall for omap_device (which
idles devices that have no drivers) and the late_initcall in
kernel/printk.c which turns off the earlyconsole.   Any printks
that happen between this omap_device late initcall and the earlyconsole
late initcall will crash when accessing the UART.

The fix is to ensure the omap_device initcall happens after the
earlyconsole initcall.

Reported-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Kevin Hilman <khilman@linaro.org>
---
Based on v3.9-rc8

 arch/arm/mach-omap2/omap_device.c | 2 +-
 arch/arm/mach-omap2/soc.h         | 1 +
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/arm/mach-omap2/omap_device.c b/arch/arm/mach-omap2/omap_device.c
index 381be7a..2d20d69 100644
--- a/arch/arm/mach-omap2/omap_device.c
+++ b/arch/arm/mach-omap2/omap_device.c
@@ -879,4 +879,4 @@ static int __init omap_device_late_init(void)
 	bus_for_each_dev(&platform_bus_type, NULL, NULL, omap_device_late_idle);
 	return 0;
 }
-omap_late_initcall(omap_device_late_init);
+omap_late_initcall_sync(omap_device_late_init);
diff --git a/arch/arm/mach-omap2/soc.h b/arch/arm/mach-omap2/soc.h
index c62116b..de88611 100644
--- a/arch/arm/mach-omap2/soc.h
+++ b/arch/arm/mach-omap2/soc.h
@@ -494,6 +494,7 @@ level(__##fn);
 #define omap_subsys_initcall(fn)	omap_initcall(subsys_initcall, fn)
 #define omap_device_initcall(fn)	omap_initcall(device_initcall, fn)
 #define omap_late_initcall(fn)		omap_initcall(late_initcall, fn)
+#define omap_late_initcall_sync(fn)	omap_initcall(late_initcall_sync, fn)
 
 #endif	/* __ASSEMBLY__ */
 
-- 
1.8.2

             reply	other threads:[~2013-05-07 21:39 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-05-07 21:39 Kevin Hilman [this message]
2013-05-08 23:17 ` [PATCH] ARM: OMAP2+: omap_device: use late_initcall_sync Tony Lindgren

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1367962765-13912-1-git-send-email-khilman@linaro.org \
    --to=khilman@linaro.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).