[ofa-general] Re: [PATCH V2] IB/mlx4: enable MSI-X by default

[Michael S. Tsirkin]

> Quoting Roland Dreier <rdreier at cisco.com>:
> Subject: Re: [PATCH V2] IB/mlx4: enable MSI-X by default
> 
>  >  		mlx4_err(dev, "NOP command failed to generate interrupt "
>  >  			 "(IRQ %d), aborting.\n",
>  >  			 priv->eq_table.eq[MLX4_EQ_ASYNC].irq);
>  > -		if (dev->flags & MLX4_FLAG_MSI_X)
>  > -			mlx4_err(dev, "Try again with MSI-X disabled.\n");
>  > -		else
>  > -			mlx4_err(dev, "BIOS or ACPI interrupt routing problem?\n");
>  > +		mlx4_err(dev, "BIOS or ACPI interrupt routing problem?\n");
> 
> This means that if MSI-X doesn't work on a system, then the user will
> see something like
> 
>     <dev> NOP command failed to generate interrupt (IRQ XXX), aborting.
>     <dev> BIOS or ACPI interrupt routing problem?
> 
> but then things will probably go on and work, right?
> 
> Which seems quite confusing.

Why doesn't MSI-X work? Isn't this BIOS problem?

> I think the code should be changed so that the message above is
> displayed (as before) if INTx interrupts fail, but if MSI-X fails,
> then do something like
> 
> 	mlx4_warn(dev, "MSI-X did not work; trying legacy INTx interrupt.\n");
> 
> (and similarly for mthca too).

We can do this.

-- 
MST