2012-08-08 18:44:01

by Stephan Linz

Subject: [PATCH v2] microblaze: improve failure handling for GPIO reset

Early exit from of_platform_reset_gpio_probe() if there
was no GPIO reset line configured.

Avoid kernel oops in gpio_system_reset():

[ 96.603690] Restarting system.
[ 96.606094] Machine restart...
[ 96.608810] Oops: kernel access of bad area, sig: 11
[ 96.613662] Registers dump: mode=824C1D1C
[ 96.617858] r1=C000BB0C, r2=00000000, r3=FFFFFEF8, r4=000015B4
[ 96.623736] r5=C0276270, r6=00000001, r7=FFFFFFFF, r8=000015B4
[ 96.629597] r9=000015B3, r10=000015B4, r11=00000000, r12=00000000
[ 96.635733] r13=00000000, r14=0000000F, r15=C0002B04, r16=00000000
[ 96.641973] r17=C011E1A0, r18=80000115, r19=00000010, r20=48184ED8
[ 96.648184] r21=00000000, r22=FFFFFFEA, r23=00000001, r24=FEE1DEAD
[ 96.654396] r25=00000054, r26=1000B1C8, r27=00000000, r28=00000000
[ 96.660622] r29=00000000, r30=00000000, r31=C24A97E0, rPC=C011E1A0
[ 96.666849] msr=000042A2, ear=0000004C, esr=00000872, fsr=362E3639

Signed-off-by: Stephan Linz <[email protected]>
---
v2 Remove additional printk message from machine_restart()
---
arch/microblaze/kernel/reset.c | 6 +++++-
1 files changed, 5 insertions(+), 1 deletions(-)

diff --git a/arch/microblaze/kernel/reset.c b/arch/microblaze/kernel/reset.c
index 8d663d9..c021123 100644
--- a/arch/microblaze/kernel/reset.c
+++ b/arch/microblaze/kernel/reset.c
@@ -28,6 +28,7 @@ void of_platform_reset_gpio_probe(void)
if (!gpio_is_valid(handle)) {
printk(KERN_INFO "Skipping unavailable RESET gpio %d (%s)\n",
handle, "reset");
+ return;
}

ret = gpio_request(handle, "reset");
@@ -60,7 +61,10 @@ err:

static void gpio_system_reset(void)
{
- gpio_set_value(handle, 1 - reset_val);
+ if (gpio_is_valid(handle))
+ gpio_set_value(handle, 1 - reset_val);
+ else
+ printk(KERN_NOTICE "Reset GPIO unavailable - halting!\n");
}
#else
static void gpio_system_reset(void)
--
1.7.0.4

2012-08-22 06:02:27

by Peter Crosthwaite

Subject: Re: [PATCH v2] microblaze: improve failure handling for GPIO reset

On Thu, Aug 9, 2012 at 4:43 AM, Stephan Linz <[email protected]> wrote:
> Early exit from of_platform_reset_gpio_probe() if there
> was no GPIO reset line configured.
>
> Avoid kernel oops in gpio_system_reset():
>
> [ 96.603690] Restarting system.
> [ 96.606094] Machine restart...
> [ 96.608810] Oops: kernel access of bad area, sig: 11
> [ 96.613662] Registers dump: mode=824C1D1C
> [ 96.617858] r1=C000BB0C, r2=00000000, r3=FFFFFEF8, r4=000015B4
> [ 96.623736] r5=C0276270, r6=00000001, r7=FFFFFFFF, r8=000015B4
> [ 96.629597] r9=000015B3, r10=000015B4, r11=00000000, r12=00000000
> [ 96.635733] r13=00000000, r14=0000000F, r15=C0002B04, r16=00000000
> [ 96.641973] r17=C011E1A0, r18=80000115, r19=00000010, r20=48184ED8
> [ 96.648184] r21=00000000, r22=FFFFFFEA, r23=00000001, r24=FEE1DEAD
> [ 96.654396] r25=00000054, r26=1000B1C8, r27=00000000, r28=00000000
> [ 96.660622] r29=00000000, r30=00000000, r31=C24A97E0, rPC=C011E1A0
> [ 96.666849] msr=000042A2, ear=0000004C, esr=00000872, fsr=362E3639
>
> Signed-off-by: Stephan Linz <[email protected]>

Tested-by: Peter Crosthwaite <[email protected]>

> ---
> v2 Remove additional printk message from machine_restart()
> ---
> arch/microblaze/kernel/reset.c | 6 +++++-
> 1 files changed, 5 insertions(+), 1 deletions(-)
>
> diff --git a/arch/microblaze/kernel/reset.c b/arch/microblaze/kernel/reset.c
> index 8d663d9..c021123 100644
> --- a/arch/microblaze/kernel/reset.c
> +++ b/arch/microblaze/kernel/reset.c
> @@ -28,6 +28,7 @@ void of_platform_reset_gpio_probe(void)
> if (!gpio_is_valid(handle)) {
> printk(KERN_INFO "Skipping unavailable RESET gpio %d (%s)\n",
> handle, "reset");
> + return;
> }
>
> ret = gpio_request(handle, "reset");
> @@ -60,7 +61,10 @@ err:
>
> static void gpio_system_reset(void)
> {
> - gpio_set_value(handle, 1 - reset_val);
> + if (gpio_is_valid(handle))
> + gpio_set_value(handle, 1 - reset_val);
> + else
> + printk(KERN_NOTICE "Reset GPIO unavailable - halting!\n");
> }
> #else
> static void gpio_system_reset(void)
> --
> 1.7.0.4
>
> --
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2012-08-24 09:02:21

by Michal Simek

Subject: Re: [PATCH v2] microblaze: improve failure handling for GPIO reset

On 08/22/2012 08:02 AM, Peter Crosthwaite wrote:
> On Thu, Aug 9, 2012 at 4:43 AM, Stephan Linz <[email protected]> wrote:
>> Early exit from of_platform_reset_gpio_probe() if there
>> was no GPIO reset line configured.
>>
>> Avoid kernel oops in gpio_system_reset():
>>
>> [ 96.603690] Restarting system.
>> [ 96.606094] Machine restart...
>> [ 96.608810] Oops: kernel access of bad area, sig: 11
>> [ 96.613662] Registers dump: mode=824C1D1C
>> [ 96.617858] r1=C000BB0C, r2=00000000, r3=FFFFFEF8, r4=000015B4
>> [ 96.623736] r5=C0276270, r6=00000001, r7=FFFFFFFF, r8=000015B4
>> [ 96.629597] r9=000015B3, r10=000015B4, r11=00000000, r12=00000000
>> [ 96.635733] r13=00000000, r14=0000000F, r15=C0002B04, r16=00000000
>> [ 96.641973] r17=C011E1A0, r18=80000115, r19=00000010, r20=48184ED8
>> [ 96.648184] r21=00000000, r22=FFFFFFEA, r23=00000001, r24=FEE1DEAD
>> [ 96.654396] r25=00000054, r26=1000B1C8, r27=00000000, r28=00000000
>> [ 96.660622] r29=00000000, r30=00000000, r31=C24A97E0, rPC=C011E1A0
>> [ 96.666849] msr=000042A2, ear=0000004C, esr=00000872, fsr=362E3639
>>
>> Signed-off-by: Stephan Linz <[email protected]>
>
> Tested-by: Peter Crosthwaite <[email protected]>
>
>> ---
>> v2 Remove additional printk message from machine_restart()
>> ---
>> arch/microblaze/kernel/reset.c | 6 +++++-
>> 1 files changed, 5 insertions(+), 1 deletions(-)

I have added it to my next branch to the previous patch.

Thanks,
Michal


--
Michal Simek, Ing. (M.Eng)
w: http://www.monstr.eu p: +42-0-721842854
Maintainer of Linux kernel 2.6 Microblaze Linux - http://www.monstr.eu/fdt/
Microblaze U-BOOT custodian