[PATCH] ARM: allow, but warn, when issuing ioremap() on RAM

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From: Felipe Contreras
Date: Thursday, October 7, 2010 - 2:44 am

Many drivers are broken, and there's no alternative in sight. Such a big
change should stay as a warning for now, and only later should it
actually fail.

The drivers are not doing something correct, we get it, but for now it's
better to allow them to work (they do 99% of the time anyway) rather
than to force everyone to revert this patch in their internal trees
until there's a solution. A slightly broken functionality is better than
no functionality at all.

A warning lets people know that what they are doing is not right, and
they should fix it.

Cc: Han Jonghun <jonghun79.han@gmail.com>
Cc: Hemant Pedanekar <hemantp@ti.com>
Cc: Arnd Hannemann <arnd@arndnet.de>
Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
---
 arch/arm/mm/ioremap.c |    3 +--
 1 files changed, 1 insertions(+), 2 deletions(-)

For issues related to this:
http://article.gmane.org/gmane.linux.ports.arm.kernel/84454
http://article.gmane.org/gmane.linux.ports.sh.devel/8560
http://www.spinics.net/lists/linux-fbdev/msg01745.html
http://article.gmane.org/gmane.linux.drivers.video-input-infrastructure/22271

diff --git a/arch/arm/mm/ioremap.c b/arch/arm/mm/ioremap.c
index ab50627..ccff7da 100644
--- a/arch/arm/mm/ioremap.c
+++ b/arch/arm/mm/ioremap.c
@@ -204,8 +204,7 @@ void __iomem * __arm_ioremap_pfn_caller(unsigned long pfn,
 	/*
 	 * Don't allow RAM to be mapped - this causes problems with ARMv6+
 	 */
-	if (WARN_ON(pfn_valid(pfn)))
-		return NULL;
+	WARN_ON(pfn_valid(pfn));
 
 	type = get_mem_type(mtype);
 	if (!type)
-- 
1.7.3.1.2.g7fe2b

--
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Messages in current thread:
[PATCH] ARM: allow, but warn, when issuing ioremap() on RAM, Felipe Contreras, (Thu Oct 7, 2:44 am)
Re: [PATCH v2] ARM: allow, but warn, when issuing ioremap( ..., Uwe Kleine-König, (Thu Oct 7, 11:00 am)
Re: [PATCH] ARM: allow, but warn, when issuing ioremap() o ..., Russell King - ARM Linux, (Thu Oct 7, 12:22 pm)
Re: [PATCH] ARM: allow, but warn, when issuing ioremap() o ..., Russell King - ARM Linux, (Fri Oct 8, 10:53 am)
Re: [PATCH] ARM: allow, but warn, when issuing ioremap() o ..., Russell King - ARM Linux, (Fri Oct 8, 4:04 pm)
Re: [PATCH] ARM: allow, but warn, when issuing ioremap() o ..., Russell King - ARM Linux, (Fri Oct 8, 4:44 pm)
Re: [PATCH] ARM: allow, but warn, when issuing ioremap() o ..., Russell King - ARM Linux, (Fri Oct 8, 5:10 pm)
Re: [PATCH] ARM: allow, but warn, when issuing ioremap() o ..., Russell King - ARM Linux, (Fri Oct 8, 5:25 pm)
Re: [PATCH] ARM: allow, but warn, when issuing ioremap() o ..., Russell King - ARM Linux, (Sat Oct 9, 1:56 am)
Re: [PATCH] ARM: allow, but warn, when issuing ioremap() o ..., Russell King - ARM Linux, (Sat Oct 9, 2:21 am)
Re: [PATCH] ARM: allow, but warn, when issuing ioremap() o ..., Russell King - ARM Linux, (Sat Oct 9, 5:05 am)
Re: [PATCH] ARM: allow, but warn, when issuing ioremap() o ..., Russell King - ARM Linux, (Sat Oct 9, 6:52 am)
Re: [PATCH] ARM: allow, but warn, when issuing ioremap() o ..., Russell King - ARM Linux, (Sat Oct 9, 7:37 am)
Re: [PATCH] ARM: allow, but warn, when issuing ioremap() o ..., Russell King - ARM Linux, (Sat Oct 9, 9:45 am)
Re: [PATCH] ARM: allow, but warn, when issuing ioremap() o ..., Guennadi Liakhovetski, (Sat Oct 9, 11:59 am)
RE: [PATCH] ARM: allow, but warn, when issuing ioremap() o ..., Pedanekar, Hemant, (Sun Oct 10, 7:23 am)
Re: [PATCH] ARM: allow, but warn, when issuing ioremap() o ..., Uwe Kleine-König, (Mon Oct 11, 1:35 am)
Re: [PATCH] ARM: allow, but warn, when issuing ioremap() o ..., Russell King - ARM Linux, (Mon Oct 11, 2:02 am)
Re: [PATCH] ARM: allow, but warn, when issuing ioremap() o ..., Uwe Kleine-König, (Mon Oct 11, 2:24 am)
Re: [PATCH] ARM: allow, but warn, when issuing ioremap() o ..., Russell King - ARM Linux, (Mon Oct 11, 3:15 am)
Re: [PATCH] ARM: allow, but warn, when issuing ioremap() o ..., Russell King - ARM Linux, (Mon Oct 11, 3:52 am)
Re: [PATCH] ARM: allow, but warn, when issuing ioremap() o ..., Russell King - ARM Linux, (Mon Oct 11, 8:25 am)
RE: [PATCH] ARM: allow, but warn, when issuing ioremap() o ..., Woodruff, Richard, (Wed Oct 13, 9:17 am)
RE: [PATCH] ARM: allow, but warn, when issuing ioremap() o ..., Woodruff, Richard, (Thu Oct 14, 8:29 am)
Re: [PATCH] ARM: allow, but warn, when issuing ioremap() o ..., Felipe Contreras, (Thu Oct 14, 10:44 am)
Re: [PATCH] ARM: allow, but warn, when issuing ioremap() o ..., Benjamin Herrenschmidt, (Fri Oct 15, 7:36 pm)
Re: [PATCH] ARM: allow, but warn, when issuing ioremap() o ..., Benjamin Herrenschmidt, (Fri Oct 15, 7:39 pm)
RE: [PATCH] ARM: allow, but warn, when issuing ioremap() o ..., Woodruff, Richard, (Sun Oct 17, 6:05 am)
RE: [PATCH] ARM: allow, but warn, when issuing ioremap() o ..., Benjamin Herrenschmidt, (Sun Oct 17, 4:17 pm)
Re: [PATCH] ARM: allow, but warn, when issuing ioremap() o ..., Russell King - ARM Linux, (Tue Oct 19, 11:12 am)
Re: [PATCH] ARM: allow, but warn, when issuing ioremap() o ..., Russell King - ARM Linux, (Tue Oct 19, 12:21 pm)
Re: About multi-line printk and the need (not) to repeat l ..., Uwe Kleine-König, (Tue Nov 23, 3:39 am)
Re: About multi-line printk and the need (not) to repeat l ..., Uwe Kleine-König, (Tue Nov 23, 3:58 am)
Re: About multi-line printk and the need (not) to repeat l ..., Russell King - ARM Linux, (Tue Nov 23, 3:33 pm)
Re: About multi-line printk and the need (not) to repeat l ..., Uwe Kleine-König, (Wed Nov 24, 1:17 am)
[PATCH 0/6] add some KERN_CONT markers to continuation lines, Uwe Kleine-König, (Wed Nov 24, 1:56 am)
[PATCH 1/6] ARM: add some KERN_CONT markers to continuatio ..., =?UTF-8?q?Uwe=20Klei ..., (Wed Nov 24, 1:57 am)
[PATCH 2/6] block: add some KERN_CONT markers to continuat ..., =?UTF-8?q?Uwe=20Klei ..., (Wed Nov 24, 1:57 am)
[PATCH 3/6] net: add some KERN_CONT markers to continuatio ..., =?UTF-8?q?Uwe=20Klei ..., (Wed Nov 24, 1:57 am)
[PATCH 4/6] init: add some KERN_CONT markers to continuati ..., =?UTF-8?q?Uwe=20Klei ..., (Wed Nov 24, 1:57 am)
[PATCH 5/6] mm: add some KERN_CONT markers to continuation ..., =?UTF-8?q?Uwe=20Klei ..., (Wed Nov 24, 1:57 am)
[PATCH 6/6] tty/vt: add some KERN_CONT markers to continua ..., =?UTF-8?q?Uwe=20Klei ..., (Wed Nov 24, 1:57 am)
Re: About multi-line printk and the need (not) to repeat l ..., Michał Mirosław, (Wed Nov 24, 2:09 am)