Send IPC message from an Interrupt handler (in an irq context)

Roelof Berg

Other Parts Discussed in Thread: SYSBIOS

Hello,

in my SYSBIOS application I can use functions like MessageQ_put() and MessageQ_create() from a Task.create()-Context. But when I try to call this functions when I'm in an IRQ (Interrupt handler) this methods never return. What would be a good practice to send an IPC message from an IRQ-context.

Ideas:

- Is it the designed behavior of sysbios that this methods hang when called from an IRQ ? (Or is this allready some Kind of error)

- Is there something as tasklets (like in Linux) or dsr (like in ecos) which one should use in SYSBIOS ?

- Or should one Task wait for a signal set by the IRQ ? (What mechanism can be recommended, just give me the buzzword)

What's a good practice to send an IPC (sharedmem) message from an IRQ handler (PCIe Interrupt 4 on DSPC-8681 with four TI C6678).

Thanks a lot,

Roelof

over 11 years ago

0 Roelof Berg over 11 years ago

Intellectual 640 points

Hello,

here's the solution I found by just using a Semaphore:

#include <xdc/cfg/global.h>
#include <ti/sysbios/knl/Semaphore.h>

void irq_handler (UArg Params) {
...
Semaphore_post(pcie_semaphore);
}

int master_main() {
    while(1) {
    Semaphore_pend(pcie_semaphore, BIOS_WAIT_FOREVER);
    hprpc_irq_process();
    }
}

void hprpc_irq_process() {
... IPC like MessageQ_Put() can be used here as we are in a clean Task context.
}

---------------------------------------------------------------
.cfg file:

var Sem = xdc.useModule ('ti.sysbios.knl.Semaphore');
var sem0Params = new Sem.Params();
sem0Params.instance.name = "pcie_semaphore";
sem0Params.mode = Sem.Mode_BINARY;
Program.global.pcie_semaphore = Sem.create(null, sem0Params);

var Task    =   xdc.useModule('ti.sysbios.knl.Task');
var tskMainThread        = Task.create("&master_main");
tskMainThread.stackSize = 0x2000;
tskMainThread.priority   = 0x5;
tskMainThread.instance.name = "master_main";

0 Kenia Guinto over 9 years ago in reply to Roelof Berg

TI__Expert 7250 points

Glad to see this was resolved.

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Send IPC message from an Interrupt handler (in an irq context)