Re: [PATCH] msi-x: let drivers retry when not enough vectors

Michael Ellerman wrote:

Not to mention that there's no guarantee that you'll get as many
interrupts as the device supports, so you should really be coding to
cope with that anyway. Like the example in MSI-HOWTO.txt:

197 static int foo_driver_enable_msix(struct foo_adapter *adapter, int nvec)
198 {
199         while (nvec >= FOO_DRIVER_MINIMUM_NVEC) {
200                 rc = pci_enable_msix(adapter->pdev,
201                                      adapter->msix_entries, nvec);
202                 if (rc > 0)
203                         nvec = rc;
204                 else
205                         return rc;
206         }
207 
208         return -ENOSPC;
209 }

So I agree, this patch is an improvement.
  

I imagine this loop is present in many drivers.  So why not add a helper

static int pci_enable_msix_min(struct foo_adapter *adapter, int min_nvec)
{
	int nvec = 2048;

        while (nvec >= min_nvec) {
                rc = pci_enable_msix(adapter->pdev,
                                     adapter->msix_entries, nvec);
                if (rc == 0)
                        return nvec;
                else if (rc > 0)
                        nvec = rc;
                else
                        return rc;
        }
        return -ENOSPC;
}



-- 
error compiling committee.c: too many arguments to function