From 191d5eca2405b58cece0e572f694abd1230b0efe Mon Sep 17 00:00:00 2001 From: Stephan Linz Date: Wed, 20 Jun 2012 22:36:37 +0200 Subject: [PATCH] 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(): [ 27.413294] Restarting system. [ 27.415674] Machine restart... [ 27.418787] Oops: kernel access of bad area, sig: 11 [ 27.423252] Registers dump: mode=83871D1C [ 27.427428] r1=00000000, r2=00000000, r3=FFFFFEF8, r4=00000000 [ 27.433310] r5=C026AED0, r6=00000001, r7=00000068, r8=00000000 [ 27.439189] r9=C3871DAC, r10=000011A5, r11=00000000, r12=0000000A [ 27.445318] r13=00000000, r14=0000000F, r15=C00029BC, r16=00000000 [ 27.451558] r17=C011DE8C, r18=80000115, r19=0000000F, r20=48184ED8 [ 27.457770] r21=00000000, r22=FFFFFFEA, r23=00000001, r24=FEE1DEAD [ 27.463982] r25=00000054, r26=1000B1C8, r27=00000000, r28=00000000 [ 27.470208] r29=00000000, r30=00000000, r31=C32D30C0, rPC=C011DE8C [ 27.476433] msr=000042A2, ear=0000004B, esr=00000872, fsr=342E3732 And remove useless dump_stack from machine_restart. Signed-off-by: Stephan Linz Signed-off-by: Michal Simek --- arch/microblaze/kernel/reset.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/arch/microblaze/kernel/reset.c b/arch/microblaze/kernel/reset.c index 88a01636f785..6ce60fb24ac5 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 @@ void of_platform_reset_gpio_probe(void) 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 + pr_notice("Reset GPIO unavailable - halting!\n"); } #else #define gpio_system_reset() do {} while (0) @@ -74,7 +78,6 @@ void machine_restart(char *cmd) { printk(KERN_NOTICE "Machine restart...\n"); gpio_system_reset(); - dump_stack(); while (1) ; }