Re: [PATCH v4 5/5] dmaengine: mediatek: fix zalloc-simple.cocci warnings

[Julia Lawall]

On Fri, 9 Feb 2018, Vinod Koul wrote:

> On Fri, Feb 09, 2018 at 01:58:51AM +0800, sean.wang@xxxxxxxxxxxx wrote:
> > From: Fengguang Wu <fengguang.wu@xxxxxxxxx>
> >
> >  Use zeroing allocator rather than allocator followed by memset with 0
> >
> > Generated by: scripts/coccinelle/api/alloc/zalloc-simple.cocci
> >
> > Fixes: c8e4b2e4ca21 ("dmaengine: mediatek: Add MediaTek High-Speed DMA controller for MT7622 and MT7623 SoC")
> > Cc: Sean Wang <sean.wang@xxxxxxxxxxxx>
> > Signed-off-by: Fengguang Wu <fengguang.wu@xxxxxxxxx>
> > Signed-off-by: Julia Lawall <julia.lawall@xxxxxxx>
> > Signed-off-by: Sean Wang <sean.wang@xxxxxxxxxxxx>
> > ---
> >  drivers/dma/mediatek/mtk-hsdma.c | 6 ++----
> >  1 file changed, 2 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/dma/mediatek/mtk-hsdma.c b/drivers/dma/mediatek/mtk-hsdma.c
> > index 42b5b23..d3b90fe 100644
> > --- a/drivers/dma/mediatek/mtk-hsdma.c
> > +++ b/drivers/dma/mediatek/mtk-hsdma.c
> > @@ -325,13 +325,11 @@ static int mtk_hsdma_alloc_pchan(struct mtk_hsdma_device *hsdma,
> >  	 * and [MTK_DMA_SIZE ... 2 * MTK_DMA_SIZE - 1] is for RX ring.
> >  	 */
> >  	pc->sz_ring = 2 * MTK_DMA_SIZE * sizeof(*ring->txd);
> > -	ring->txd = dma_alloc_coherent(hsdma2dev(hsdma),
> > -				       pc->sz_ring, &ring->tphys,
> > -				       GFP_ATOMIC | __GFP_ZERO);
> > +	ring->txd = dma_zalloc_coherent(hsdma2dev(hsdma), pc->sz_ring,
> > +					&ring->tphys, GFP_ATOMIC);
> >  	if (!ring->txd)
> >  		return -ENOMEM;
> >
> > -	memset(ring->txd, 0, pc->sz_ring);
>
> This should be folded back..

Sorry, I'm not sure what you mean by "folded back".

julia

>
> >  	ring->rxd = &ring->txd[MTK_DMA_SIZE];
> >  	ring->rphys = ring->tphys + MTK_DMA_SIZE * sizeof(*ring->txd);
> >  	ring->cur_tptr = 0;
> > --
> > 2.7.4
> >
>
> --
> ~Vinod
>