MSI Interrupt Latency

ZAKARIA BOURZOUK

Hi,

in my application , the EP sends 200 interruptions to RC , but the problem is that the RC does not capture all interrupts , it receives only 160 !!

I use task_sleep() function that defines the number of cycles between two interruptions, and I try increase and decrease this time, but I do not always pick up 200.

EP routine :

VOID MsiTrigger() {
INT32 i, j;

/* Wait for link to be up */
PCIe_WaitLinkUp(handle);

System_printf("Link is up #EP.\n");

for (j = 1; j <= 200; j++) {
Msiwrite();
Task_sleep(1);

}

exit(0);

}

can you give me an explanation of this problem please ?!

thank you,

Sincerely,

Zakaria.

over 10 years ago

0 Ganapathi Dhandapani95 over 10 years ago

TI__Mastermind 28085 points

Hi,

If you want to use the MSI interrupts continuously means, you need to update EOI bits on IRQ_EOI register. (Example: you using MSI0 means write 0x4 to IRQ_EOI register /* end of MSI0, event number=4 */) Refer section 3.1.15 End of Interrupt Register (IRQ_EOI) on PCIe user guide.

Please refer the following thread. Hope it helps.

e2e.ti.com/.../161475.aspx

Thanks,

0 ZAKARIA BOURZOUK over 10 years ago in reply to Ganapathi Dhandapani95

Intellectual 560 points

Hi,

Yes i no , i do it :

RC routine :

VOID hwi_isr() {

pcieRegisters_t setRegs;
pcieMsiIrqStatusReg_t msiIrqStatus[1];
pcieIrqEOIReg_t irqEOI;
volatile UINT32 *MSI0_IRQ0;

memset(&irqEOI, 0, sizeof(irqEOI));
memset(&setRegs, 0, sizeof(setRegs));
memset(&msiIrqStatus, 0, sizeof(msiIrqStatus));

MSI0_IRQ0 = ((UINT32 *) 0x21800104);

if (*MSI0_IRQ0 == 1) {
MSIlaunched++;
}

msiIrqStatus[0].msiIrqStatus = 0xF;
irqEOI.EOI = 0x4;

setRegs.msiIrqStatus[0] = &msiIrqStatus[0];
setRegs.irqEOI = &irqEOI;

return;
}

thank you,

Sincerely,

Zakaria.

0 Ganapathi Dhandapani95 over 10 years ago in reply to ZAKARIA BOURZOUK

TI__Mastermind 28085 points

Hi,

What is the intention for your testing? Have you tried the PCIe legacy interrupt?

Thanks,

0 ZAKARIA BOURZOUK over 10 years ago in reply to Ganapathi Dhandapani95

Intellectual 560 points

Hi,

normally in applications all interruptions must be taken into concideration, so we do not have the right to ignore an interruption!!
No, I just work with MSI Interrupt .

thank you,

Sincerely,

Zakaria.

0 ZAKARIA BOURZOUK over 10 years ago in reply to ZAKARIA BOURZOUK

Intellectual 560 points

Hi,

All right, I solved my problem.

it was because printf , they consumed more cycles that slows send traps.

Sincerely,

Zakaria.

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MSI Interrupt Latency