[patch 01/39] PCI/MSI: Check for MSI enabled in __pci_msix_enable()

[Ashok Raj]

On Fri, Nov 11, 2022 at 02:54:15PM +0100, Thomas Gleixner wrote:
> PCI/MSI and PCI/MSI-X are mutually exclusive, but the MSI-X enable code
> lacks a check for already enabled MSI.
> 
> Signed-off-by: Thomas Gleixner <tglx at linutronix.de>
> ---
>  drivers/pci/msi/msi.c |    5 +++++
>  1 file changed, 5 insertions(+)
> 
> --- a/drivers/pci/msi/msi.c
> +++ b/drivers/pci/msi/msi.c
> @@ -935,6 +935,11 @@ static int __pci_enable_msix_range(struc
>  	if (maxvec < minvec)
>  		return -ERANGE;
>  
> +	if (dev->msi_enabled) {
> +		pci_info(dev, "can't enable MSI-X (MSI already enabled)\n");
> +		return -EINVAL;
> +	}
> +

nit: 

Can the pre-enabled checks for msi and msix be moved up before any vector
range check?

not that it matters for how it fails, does EBUSY sound better?

looks good.

Reviewed-by: Ashok Raj <ashok.raj at intel.com>

>  	if (WARN_ON_ONCE(dev->msix_enabled))
>  		return -EINVAL;