RE: [PATCH] omap: wd_timer: Fix crash frm wdt_probe when !CONFIG_RUNTIME_PM

Santosh Shilimkar
2011-01-05T13:53:10Z

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> -----Original Message-----
> From: Santosh Shilimkar [mailto:santosh.shilimkar@ti.com]
> Sent: Wednesday, January 05, 2011 7:11 PM
> To: linux-omap@vger.kernel.org
> Cc: linux-arm-kernel@lists.infradead.org; Santosh Shilimkar; Paul
> Walmsley
> Subject: [PATCH] omap: wd_timer: Fix crash frm wdt_probe when
> !CONFIG_RUNTIME_PM
>
(Removing unnecessary changes which got committed by mistake)

>From c9c34f9bcff789bb2354c299e2c47aa74c8c07ed Mon Sep 17 00:00:00 2001
From: Santosh Shilimkar <santosh.shilimkar@ti.com>
Date: Wed, 5 Jan 2011 18:41:20 +0530
Subject: [PATCH] omap: wd_timer: Fix crash frm wdt_probe when
!CONFIG_RUNTIME_PM

Commit ff2516fb 'wd_timer: disable on boot via hwmod postsetup mechanism'
introduced watchdog timer state state management using postsetup_state.
This was done to allow some board files to support watchdog coverage
throughout kernel initialization and it work as intended when RUNTIME_PM
is enabled.

With !CONFIG_RUNTIME_PM and no board is specifically requests watchdog
to remain enabled the omap_wdt_probe crashesh. This is because hwmod
in absense of runtime PM unable to turn watchdog clocks because it's
state is set to be disabled. For rest of the device, the state is
set as enabled in absense of RUNTIME_PM

[ 1.372558] Unhandled fault: imprecise external abort (0x1406) at
0xad733eeb
[ 1.379913] Internal error: : 1406 [#1] SMP
[ 1.384277] last sysfs file:
[ 1.387359] Modules linked in:
[ 1.390563] CPU: 0 Tainted: G W
(2.6.37-rc7-00265-g4298a4c-dirty #23)
[ 1.398468] PC is at omap_wdt_disable+0x2c/0x3c
[ 1.403198] LR is at omap_wdt_probe+0x124/0x1e0
[ 1.407928] pc : [<c02f5bf4>] lr : [<c03be10c>] psr: 60000013
[ 1.407958] sp : df833f00 ip : 00000000 fp : 00000000
[ 1.419921] r10: c0ac57ac r9 : df959e00 r8 : 00000000
[ 1.425384] r7 : df959e08 r6 : df8000c0 r5 : df95bebc r4 : df87dde0
[ 1.432189] r3 : fc314000 r2 : 00005555 r1 : fc314034 r0 : df87dde0

This patch make the default watchdog state to be enabled in case of
!CONFIG_RUNTIME_PM. This fixes the crash

Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Cc: Paul Walmsley <paul@pwsan.com>
---
Paul, I am not too sure if it breaks your _shutdown idea of watchdog
timer.
Patch generated against 'omap-for-linus' branch and boot tested on OMAP4
with and without CONFIG_OMAP_WATCHDOG.

arch/arm/mach-omap2/io.c | 4 ++++
1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/arch/arm/mach-omap2/io.c b/arch/arm/mach-omap2/io.c
index e66687b..b879a16 100644
--- a/arch/arm/mach-omap2/io.c
+++ b/arch/arm/mach-omap2/io.c
@@ -378,7 +378,11 @@ void __init omap2_init_common_infrastructure(void)
* XXX ideally we could detect whether the MPU WDT was currently
* enabled here and make this conditional
*/
+#ifdef CONFIG_PM_RUNTIME
postsetup_state = _HWMOD_STATE_DISABLED;
+#else
+ postsetup_state = _HWMOD_STATE_ENABLED;
+#endif
omap_hwmod_for_each_by_class("wd_timer",
_set_hwmod_postsetup_state,
&postsetup_state);
--
1.6.0.4

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From c9c34f9bcff789bb2354c299e2c47aa74c8c07ed Mon Sep 17 00:00:00 2001
From: Santosh Shilimkar <santosh.shilimkar@ti.com>
Date: Wed, 5 Jan 2011 18:41:20 +0530
Subject: [PATCH] omap: wd_timer: Fix crash frm wdt_probe when !CONFIG_RUNTIME_PM

Commit ff2516fb 'wd_timer: disable on boot via hwmod postsetup mechanism'
introduced watchdog timer state state management using postsetup_state.
This was done to allow some board files to support watchdog coverage
throughout kernel initialization and it work as intended when RUNTIME_PM
is enabled.

With !CONFIG_RUNTIME_PM and no board is specifically requests watchdog
to remain enabled the omap_wdt_probe crashesh. This is because hwmod
in absense of runtime PM unable to turn watchdog clocks because it's
state is set to be disabled. For rest of the device, the state is
set as enabled in absense of RUNTIME_PM

[ 1.372558] Unhandled fault: imprecise external abort (0x1406) at 0xad733eeb
[ 1.379913] Internal error: : 1406 [#1] SMP
[ 1.384277] last sysfs file:
[ 1.387359] Modules linked in:
[ 1.390563] CPU: 0 Tainted: G W (2.6.37-rc7-00265-g4298a4c-dirty #23)
[ 1.398468] PC is at omap_wdt_disable+0x2c/0x3c
[ 1.403198] LR is at omap_wdt_probe+0x124/0x1e0
[ 1.407928] pc : [<c02f5bf4>] lr : [<c03be10c>] psr: 60000013
[ 1.407958] sp : df833f00 ip : 00000000 fp : 00000000
[ 1.419921] r10: c0ac57ac r9 : df959e00 r8 : 00000000
[ 1.425384] r7 : df959e08 r6 : df8000c0 r5 : df95bebc r4 : df87dde0
[ 1.432189] r3 : fc314000 r2 : 00005555 r1 : fc314034 r0 : df87dde0

This patch make the default watchdog state to be enabled in case of
!CONFIG_RUNTIME_PM. This fixes the crash

Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Cc: Paul Walmsley <paul@pwsan.com>
---
Paul, I am not too sure if it breaks your _shutdown idea of watchdog
timer.
Patch generated against 'omap-for-linus' branch and boot tested on OMAP4
with and without CONFIG_OMAP_WATCHDOG.

arch/arm/mach-omap2/io.c | 4 ++++
1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/arch/arm/mach-omap2/io.c b/arch/arm/mach-omap2/io.c
index e66687b..b879a16 100644
--- a/arch/arm/mach-omap2/io.c
+++ b/arch/arm/mach-omap2/io.c
@@ -378,7 +378,11 @@ void __init omap2_init_common_infrastructure(void)
* XXX ideally we could detect whether the MPU WDT was currently
* enabled here and make this conditional
*/
+#ifdef CONFIG_PM_RUNTIME
postsetup_state = _HWMOD_STATE_DISABLED;
+#else
+ postsetup_state = _HWMOD_STATE_ENABLED;
+#endif
omap_hwmod_for_each_by_class("wd_timer",
_set_hwmod_postsetup_state,
&postsetup_state);
--
1.6.0.4