Re: [PATCH] RDMA/bng_re: Fix CREQ BAR base validity check in bng_re_map_creq_db

[Leon Romanovsky <leon@kernel.org>]

On Fri, Feb 27, 2026 at 07:35:21AM -0800, Alok Tiwari wrote:
> bng_re_map_creq_db() initializes creq_db->reg.bar_id to the fixed BAR
> index used for the CREQ doorbell, then reads the BAR start address via
> pci_resource_start().
> 
> The existing code checked !bar_id, which is not a validity test for the
> PCI resource start. Check !bar_base instead and log an error when the
> BAR start address is 0.
> 
> Fixes: 4f830cd8d7fe ("RDMA/bng_re: Add infrastructure for enabling Firmware channel")
> Signed-off-by: Alok Tiwari <alok.a.tiwari@oracle.com>
> ---
>  drivers/infiniband/hw/bng_re/bng_fw.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/infiniband/hw/bng_re/bng_fw.c b/drivers/infiniband/hw/bng_re/bng_fw.c
> index 17d7cc3aa11d..92e7fa4dcf1a 100644
> --- a/drivers/infiniband/hw/bng_re/bng_fw.c
> +++ b/drivers/infiniband/hw/bng_re/bng_fw.c
> @@ -581,7 +581,7 @@ static int bng_re_map_creq_db(struct bng_re_rcfw *rcfw, u32 reg_offt)
>  	creq_db->dbinfo.flags = 0;
>  	creq_db->reg.bar_id = BNG_FW_COMM_CONS_PCI_BAR_REGION;
>  	creq_db->reg.bar_base = pci_resource_start(pdev, creq_db->reg.bar_id);
> -	if (!creq_db->reg.bar_id)
> +	if (!creq_db->reg.bar_base)

Why is this check needed in the first place? The driver does nothing except
print an error message, which is unlikely to ever occur.

IMHO, you can remove it.

Thanks

>  		dev_err(&pdev->dev,
>  			"CREQ BAR region %d resc start is 0!",
>  			creq_db->reg.bar_id);
> -- 
> 2.50.1
>