From 630b4fc55537721c68462e71d0910a3734baa852 Mon Sep 17 00:00:00 2001 From: Michael Sevakis Date: Wed, 5 May 2010 07:15:20 +0000 Subject: i.MX31/Gigabeat S: The nested IRQ code was just totally wrong and not actually working anyway (which is why it wasn't crashing). AVIC doesn't seem truthful about priority of current ISR either :\. Sometimes there were channel swaps during really active DVFS due to FIFO underflow from a needed long delay in the ISR (100us, and IIS TX only has 45us reserve) and DMARQ *must* be serviced low-latency. Get it doing as was intended. git-svn-id: svn://svn.rockbox.org/rockbox/trunk@25822 a1c6a512-1295-4272-9138-f99709370657 --- firmware/target/arm/imx31/avic-imx31.h | 33 +++++++++++++---------------- firmware/target/arm/imx31/dvfs_dptc-imx31.c | 2 +- 2 files changed, 16 insertions(+), 19 deletions(-) (limited to 'firmware/target/arm/imx31') diff --git a/firmware/target/arm/imx31/avic-imx31.h b/firmware/target/arm/imx31/avic-imx31.h index ba8f91cc1a..43fd726db3 100644 --- a/firmware/target/arm/imx31/avic-imx31.h +++ b/firmware/target/arm/imx31/avic-imx31.h @@ -218,33 +218,30 @@ void avic_set_int_type(enum IMX31_INT_LIST ints, enum INT_TYPE intstype); #define AVIC_NIL_ENABLE 0x1f void avic_set_ni_level(unsigned int level); + /* Call a service routine while allowing preemption by interrupts of higher * priority. r4-r7 must be preserved for epilogue code to restore context. */ -#define AVIC_NESTED_NI_CALL_PROLOGUE() \ +#define AVIC_NESTED_NI_CALL_PROLOGUE(prio) \ ({ asm volatile ( \ "sub lr, lr, #4 \n" /* prepare return address */ \ - "stmfd sp!, { r0-r7, r12, lr } \n" /* preserve return context */ \ + "srsdb #0x12! \n" /* save LR_irq and SPSR_irq */ \ + "stmfd sp!, { r0-r3, r12 } \n" /* preserve context */ \ "mov r0, #0x68000000 \n" /* AVIC_BASE_ADDR */ \ - "mrs r4, spsr \n" /* save SPSR_irq */ \ - "ldr r5, [r0, #0x04] \n" /* save NIMASK */ \ - "ldr r1, [r0, #0x40] \n" /* load NIVECSR */ \ - "mov r2, sp \n" /* remember IRQ stack to use in call */ \ - "str r1, [r0, #0x04] \n" /* copy NIVECSR to NIMASK */ \ - "cps #0x13 \n" /* switch to SVC mode (+ unmask IRQ) */ \ - "mov r6, sp \n" /* save SP_svc */ \ - "mov r7, lr \n" /* save LR_svc */ \ - "mov sp, r2 \n" /* switch to SP_irq */ \ - ); }) + "mov r1, %0 \n" /* load interrupt level */ \ + "ldr r2, [r0, #0x04] \n" /* save NIMASK */ \ + "str r1, [r0, #0x04] \n" /* set interrupt level */ \ + "cpsie i, #0x13 \n" /* change to SVC mode, unmask IRQ */ \ + "stmfd sp!, { r2, lr } \n" /* push NIMASK and LR on SVC stack */ \ + : : "i"(prio)); }) #define AVIC_NESTED_NI_CALL_EPILOGUE() \ ({ asm volatile ( \ - "mov sp, r6 \n" /* restore SP_svc */ \ - "mov lr, r7 \n" /* restore LR_svc */ \ - "cps #0x12 \n" /* return to IRQ mode (+ mask IRQ) */ \ + "ldmfd sp!, { r2, lr } \n" /* pop original LR and NIMASK */ \ + "cpsid i, #0x12 \n" /* return to IRQ mode, mask IRQ */ \ "mov r0, #0x68000000 \n" /* AVIC BASE ADDR */ \ - "msr spsr_cxsf, r4 \n" /* restore SPSR_irq */ \ - "str r5, [r0, #0x04] \n" /* restore NIMASK */ \ - "ldmfd sp!, { r0-r7, r12, pc }^ \n" /* reload context and return */ \ + "str r2, [r0, #0x04] \n" /* restore NIMASK */ \ + "ldmfd sp!, { r0-r3, r12 } \n" /* reload context */ \ + "rfefd sp! \n" /* move stacked SPSR to CPSR, return */ \ ); }) #endif /* AVIC_IMX31_H */ diff --git a/firmware/target/arm/imx31/dvfs_dptc-imx31.c b/firmware/target/arm/imx31/dvfs_dptc-imx31.c index 5e1a598428..680b015c81 100644 --- a/firmware/target/arm/imx31/dvfs_dptc-imx31.c +++ b/firmware/target/arm/imx31/dvfs_dptc-imx31.c @@ -230,7 +230,7 @@ static void __attribute__((used)) dvfs_int(void) static __attribute__((naked, interrupt("IRQ"))) void CCM_DVFS_HANDLER(void) { /* Audio can glitch with the long udelay if nested IRQ isn't allowed. */ - AVIC_NESTED_NI_CALL_PROLOGUE(); + AVIC_NESTED_NI_CALL_PROLOGUE(INT_PRIO_DVFS); asm volatile ("bl dvfs_int"); AVIC_NESTED_NI_CALL_EPILOGUE(); } -- cgit v1.2.3