multiple MSI for PCIe in K2H?

Hi, Shehzad,

In the first thread, the comment was "In keystone-II implementation, only 1 interrupt per device is supported. Please see drivers/pci/host/pcie-keystone.c in which arch_setup_msi_irq() calls get_free_msi(). get_free_msi() finds the first zero bit and returns it as the interrupt to be used. To allocate multiple interrupts for the device, the application can try to make multiple calls into pci_enable_msi_block() to get multiple interrupts."

Yes, you want to make multiple calls.

Rex

Thanks Rex,

But when I try to make multiple calls to pci_enable_msi_block() , driver crashes. I checked with printk's , second call to pci_enable_msi_block() causes driver to crash. My code is as:

for (i = 0; i < 4 ; i++)

   {

     printk(KERN_DEBUG "enabling MSI %d\n", i+1);

     ret = pci_enable_msi_block(pdev,1);

     printk(KERN_DEBUG "enabed MSI %d\n", i+1);

     irq_num[i] =pdev->irq;

     printk(KERN_DEBUG "irq%d has line number = %d\n", i+1, pdev->irq);

     if(ret != 0)

     {

       printk(KERN_DEBUG "Unable to allocate MSI 1-16 return value is %d\n", ret);

       return ret;

     }

     else

     {

      printk(KERN_DEBUG "Successfully allocated MSI %d \n",i+1);

     }



Output:

enabling MSI 1

enabed MSI 1

irq1 has line number = 576

Successfully allocated MSI 1

enabling MSI 2

[ Crash].