Re: [PATCH 2/2] octeon_ep: Fix irq releasing in the error handling path of octep_request_irqs()

[Dan Carpenter <dan.carpenter@oracle.com>]

On Sun, May 15, 2022 at 05:56:45PM +0200, Christophe JAILLET wrote:
> For the error handling to work as expected, the index in the
> 'oct->msix_entries' array must be tweaked because, when the irq are
> requested there is:
> 	msix_entry = &oct->msix_entries[i + num_non_ioq_msix];
> 
> So in the error handling path, 'i + num_non_ioq_msix' should be used
> instead of 'i'.
> 
> The 2nd argument of free_irq() also needs to be adjusted.
> 
> Fixes: 37d79d059606 ("octeon_ep: add Tx/Rx processing and interrupt support")
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
> ---
> I think that the wording above is awful, but I'm sure you get it.
> Feel free to rephrase everything to have it more readable.
> ---
>  drivers/net/ethernet/marvell/octeon_ep/octep_main.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ethernet/marvell/octeon_ep/octep_main.c b/drivers/net/ethernet/marvell/octeon_ep/octep_main.c
> index 6b60a03574a0..4dcae805422b 100644
> --- a/drivers/net/ethernet/marvell/octeon_ep/octep_main.c
> +++ b/drivers/net/ethernet/marvell/octeon_ep/octep_main.c
> @@ -257,10 +257,12 @@ static int octep_request_irqs(struct octep_device *oct)
>  
>  	return 0;
>  ioq_irq_err:
> +	i += num_non_ioq_msix;
>  	while (i > num_non_ioq_msix) {

This makes my mind hurt so badly.  Can we not just have two variables
for the two different loops instead of re-using i?

>  		--i;
>  		irq_set_affinity_hint(oct->msix_entries[i].vector, NULL);
> -		free_irq(oct->msix_entries[i].vector, oct->ioq_vector[i]);
> +		free_irq(oct->msix_entries[i].vector,
> +			 oct->ioq_vector[i - num_non_ioq_msix]);
>  	}

ioq_irq_err:
        while (--j >= 0) {
                ioq_vector = oct->ioq_vector[j];
                msix_entry = &oct->msix_entries[j + num_non_ioq_msix];

                irq_set_affinity_hint(msix_entry->vector, NULL);
                free_irq(msix_entry->vector, ioq_vector);
        }

regards,
dan carpenter