-----Original Message-----
From: Menon, Nishanth
Sent: Friday, September 17, 2010 3:45 PM
To: Shilimkar, Santosh; linux-omap at vger.kernel.org
Cc: linux-arm-kernel at lists.infradead.org; Nayak, Rajendra
Subject: RE: [PATCH 14/14] omap4: Fix bootup crash observed with higher
CPU clocks

quoted

-----Original Message-----
From: linux-omap-owner at vger.kernel.org [mailto:linux-omap-
owner at vger.kernel.org] On Behalf Of Shilimkar, Santosh
Sent: Friday, September 17, 2010 4:48 AM
To: linux-omap at vger.kernel.org
Cc: linux-arm-kernel at lists.infradead.org; Shilimkar, Santosh; Nayak,
Rajendra
Subject: [PATCH 14/14] omap4: Fix bootup crash observed with higher CPU
clocks

This patch is temporary fix to below crash. This is observed when
CPU is clocked more than 600 MHz.

Unhandled fault: imprecise external abort (0x1406) at 0xbf9ef65c
Internal error: : 1406 [#1] PREEMPT SMP
last sysfs file:
Modules linked in:
CPU: 0    Not tainted  (2.6.36-rc3+ #18)
PC is at kernel_thread_helper+0x0/0x14
LR is at kernel_thread_helper+0x0/0x14
pc : [<c003ce14>]    lr : [<c003ce14>]    psr: 00000093
sp : dc83bff8  ip : 00000000  fp : 00000000
r10: 00000000  r9 : 00000000  r8 : 00000000
r7 : 00000013  r6 : c003ce28  r5 : c008935c  r4 : 00000000
r3 : 00000000  r2 : 00000000  r1 : 00000000  r0 : 00000000
Flags: nzcv  IRQs off  FIQs on  Mode SVC_32  ISA ARM  Segment kernel
Control: 10c53c7f  Table: 8000404a  DAC: 00000017
Process swapper (pid: 2, stack limit = 0xdc83a2f0)
Stack: (0xdc83bff8 to 0xdc83c000)
bfe0: 00000000 ffffffff
[<c003ce14>] (kernel_thread_helper+0x0/0x14) from [<fffffffe>]
(0xfffffffe)
Code: c03a0ba3 c03a5fcb c045c880 c0394035 (eb017701)
---[ end trace 1b75b31a2719ed1c ]---

The timer hwmod adaptation will eventually fix it in a proper way.

Signed-off-by: Rajendra Nayak <redacted>
Signed-off-by: Santosh Shilimkar <redacted>
---
 arch/arm/plat-omap/dmtimer.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/arch/arm/plat-omap/dmtimer.c b/arch/arm/plat-omap/dmtimer.c
index 44bafda..1d706cf 100644
--- a/arch/arm/plat-omap/dmtimer.c
+++ b/arch/arm/plat-omap/dmtimer.c

@@ -581,7 +581,7 @@ int omap_dm_timer_set_source(struct omap_dm_timer

*timer, int source)
 	 * When the functional clock disappears, too quick writes seem
 	 * to cause an abort. XXX Is this still necessary?
 	 */
-	__delay(150000);
+	__delay(300000);

What is the rationale for this increase? Lets say we have a CPU bumped up
to 1GHz or something will we have weird numbers again?

This is the max what we need at any clock speed. As mentioned in commit
"The timer hwmod adaptation will eventually fix it in a proper way"

Regards,
Santosh