Re: [PATCH net 1/1] nfp: correct number of MSI vectors requests returned

[Jakub Kicinski <kuba@kernel.org>]

On Thu, 16 Mar 2023 13:09:43 +0200 Leon Romanovsky wrote:
> On Wed, Mar 15, 2023 at 02:17:33PM +0200, Louis Peens wrote:
> > From: Xiaoyu Li <xiaoyu.li@corigine.com>
> > 
> > Before the referenced commit, when we requested a
> > certain number of interrupts, if we could not meet
> > the requirements, the number of interrupts supported
> > by the hardware would be returned. But after the
> > referenced commit, if the hardware failed to meet
> > the requirements, the error of invalid argument
> > would be directly returned, which caused a regression
> > in the nfp driver preventing probing to complete.  
> 
> Please don't break lines. You have upto 80 chars per-line.

72 I think, git adds an indentation. Not that I personally care
about "not using full lines".

> > diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
> > index 62f0bf91d1e1..0e4cab38f075 100644
> > --- a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
> > +++ b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
> > @@ -370,6 +370,12 @@ nfp_net_irqs_alloc(struct pci_dev *pdev, struct msix_entry *irq_entries,
> >  {
> >  	unsigned int i;
> >  	int got_irqs;
> > +	int max_irqs;
> > +
> > +	max_irqs = pci_msix_vec_count(pdev);
> > +	if (max_irqs < 0)
> > +		return max_irqs;
> > +	wanted_irqs = min_t(unsigned int, max_irqs, wanted_irqs);  
> 
> 1. It looks like you need to fix your nfp_net_irqs_alloc() to provide
> valid wanted_irqs from the beginning.

Right, why do you have this problem in the first place?
Could you provide some concrete numbers?