Re: [PATCH net] net: mvneta_bm: fix gen_pool_free address for BPPI

On Wed, Aug 05, 2026 at 02:14:38PM +0800, Chenguang Zhao wrote:
> From: Chenguang Zhao <[email protected]>
> 
> gen_pool_free() expects the virtual address returned by
> gen_pool_dma_alloc(), not the physical address. Passing phys can miss
> the chunk and trigger BUG() on remove or probe rollback.
> 
> Fixes: dc35a10f68d3 ("net: mvneta: bm: add support for hardware buffer management")
> Signed-off-by: Chenguang Zhao <[email protected]>
> ---
>  drivers/net/ethernet/marvell/mvneta_bm.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ethernet/marvell/mvneta_bm.c b/drivers/net/ethernet/marvell/mvneta_bm.c
> index 6bb380494919..2a114a69a0ab 100644
> --- a/drivers/net/ethernet/marvell/mvneta_bm.c
> +++ b/drivers/net/ethernet/marvell/mvneta_bm.c
> @@ -389,7 +389,7 @@ static int mvneta_bm_get_sram(struct device_node *dn,
>  
>  static void mvneta_bm_put_sram(struct mvneta_bm *priv)
>  {
> -	gen_pool_free(priv->bppi_pool, priv->bppi_phys_addr,
> +	gen_pool_free(priv->bppi_pool, (unsigned long)priv->bppi_virt_addr,

The cast is ugly, but it also seems correct. However, can the API be
improved. If the intention is

gen_pool_free(priv->bppi_pool,
              gen_pool_dma_alloc(priv->bppi_pool,
                                 MVNETA_BM_BPPI_SIZE,
                                 &priv->bppi_phys_addr),
              MVNETA_BM_BPPI_SIZE);

maybe gen_pool_free() should be changed to take a void *?

      Andrew