From: Haiying Wang haiying.wang@freescale.com
Prevent false interrupt from hanging Linux as MSR[EE] is set to enable interrupts by changing the PIC out of the default pass through mode into mixed mode.
Signed-off-by: Haiying Wang haiying.wang@freescale.com Signed-off-by: Jon Loeliger jdl@freescale.com --- cpu/mpc86xx/interrupts.c | 20 ++++++++++++++++++++ include/asm-ppc/immap_86xx.h | 2 ++ 2 files changed, 22 insertions(+), 0 deletions(-)
diff --git a/cpu/mpc86xx/interrupts.c b/cpu/mpc86xx/interrupts.c index 1df6cdc..49820bb 100644 --- a/cpu/mpc86xx/interrupts.c +++ b/cpu/mpc86xx/interrupts.c @@ -80,6 +80,26 @@ int interrupt_init(void) { int ret;
+ /* + * The IRQ0 on Rev 2 is pulled high (low in Rev 1.x) to + * implement PEX10 errata. As INT is active high, it + * will cause core to take 0x500 interrupt. + * + * Due to the PIC's default pass through mode, as soon + * as interrupts are enabled (MSR[EE] = 1), an interrupt + * will be taken and u-boot will hang. This is due to a + * hardware change (per an errata fix) on new revisions + * of the board with Rev 2.x parts. + * + * Setting the PIC to mixed mode prevents the hang. + */ + if ((get_svr() & 0xf0) == 0x20) { + volatile immap_t *immr = (immap_t *)CFG_IMMR; + immr->im_pic.gcr = MPC86xx_PICGCR_RST; + while (immr->im_pic.gcr & MPC86xx_PICGCR_RST); + immr->im_pic.gcr = MPC86xx_PICGCR_MODE; + } + /* call cpu specific function from $(CPU)/interrupts.c */ ret = interrupt_init_cpu(&decrementer_count);
diff --git a/include/asm-ppc/immap_86xx.h b/include/asm-ppc/immap_86xx.h index a5552c4..0e3fc34 100644 --- a/include/asm-ppc/immap_86xx.h +++ b/include/asm-ppc/immap_86xx.h @@ -721,6 +721,8 @@ typedef struct ccsr_pic { uint frr; /* 0x41000 - Feature Reporting Register */ char res10[28]; uint gcr; /* 0x41020 - Global Configuration Register */ +#define MPC86xx_PICGCR_RST 0x80000000 +#define MPC86xx_PICGCR_MODE 0x20000000 char res11[92]; uint vir; /* 0x41080 - Vendor Identification Register */ char res12[12];