From: Nicolas Dufresne <nicolas.dufresne@collabora.com>
To: Luo Qiu <luoqiu@kylinsec.com.cn>,
Benjamin Gaignard <benjamin.gaignard@collabora.com>,
Philipp Zabel <p.zabel@pengutronix.de>,
Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: linux-media@vger.kernel.org, linux-rockchip@lists.infradead.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] media: verisilicon: Remove unnecessary memset() after dma_alloc_coherent
Date: Wed, 25 Mar 2026 09:21:57 -0400 [thread overview]
Message-ID: <c90e82bc630b54419d10ee6f179bc1239060a808.camel@collabora.com> (raw)
In-Reply-To: <856D681C2A51EC65+20260325050055.1187863-1-luoqiu@kylinsec.com.cn>
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Le mercredi 25 mars 2026 à 13:00 +0800, Luo Qiu a écrit :
> dma_alloc_coherent() already returns zeroed memory, so the subsequent
> memset(0) calls are redundant.
I don't think this statement is actually true, or at least not for all
architectures, and not without an explicit GFP_ZERO flag.
Nicolas
>
> Signed-off-by: Luo Qiu <luoqiu@kylinsec.com.cn>
> ---
> drivers/media/platform/verisilicon/hantro_vp9.c | 3 ---
> 1 file changed, 3 deletions(-)
>
> diff --git a/drivers/media/platform/verisilicon/hantro_vp9.c b/drivers/media/platform/verisilicon/hantro_vp9.c
> index 566cd376c097..607d618e8f4a 100644
> --- a/drivers/media/platform/verisilicon/hantro_vp9.c
> +++ b/drivers/media/platform/verisilicon/hantro_vp9.c
> @@ -187,7 +187,6 @@ int hantro_vp9_dec_init(struct hantro_ctx *ctx)
> return -ENOMEM;
>
> tile_edge->size = size;
> - memset(tile_edge->cpu, 0, size);
>
> size = hantro_vp9_segment_map_size(max_width, max_height);
> vp9_dec->segment_map_size = size;
> @@ -198,7 +197,6 @@ int hantro_vp9_dec_init(struct hantro_ctx *ctx)
> goto err_segment_map;
>
> segment_map->size = size;
> - memset(segment_map->cpu, 0, size);
>
> size = hantro_vp9_prob_tab_size();
> vp9_dec->ctx_counters_offset = size;
> @@ -211,7 +209,6 @@ int hantro_vp9_dec_init(struct hantro_ctx *ctx)
> goto err_misc;
>
> misc->size = size;
> - memset(misc->cpu, 0, size);
>
> init_v4l2_vp9_count_tbl(ctx);
>
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prev parent reply other threads:[~2026-03-25 13:22 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-25 5:00 [PATCH] media: verisilicon: Remove unnecessary memset() after dma_alloc_coherent Luo Qiu
2026-03-25 13:21 ` Nicolas Dufresne [this message]
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