Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Subject: Re: [PATCH v4 5/5] media: meson: vdec: add VP9 decoder support
To:     Neil Armstrong <narmstrong@baylibre.com>, mchehab@kernel.org,
        hans.verkuil@cisco.com
Cc:     Maxime Jourdan <mjourdan@baylibre.com>,
        linux-media@vger.kernel.org, linux-amlogic@lists.infradead.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
References: <20200206084152.7070-1-narmstrong@baylibre.com>
 <20200206084152.7070-6-narmstrong@baylibre.com>
From:   Hans Verkuil <hverkuil@xs4all.nl>
Message-ID: <444673d2-f1f0-bfe8-1aa2-b37cbdec6231@xs4all.nl>
Date:   Fri, 14 Feb 2020 16:04:49 +0100
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101
 Thunderbird/68.4.2
MIME-Version: 1.0
In-Reply-To: <20200206084152.7070-6-narmstrong@baylibre.com>
Content-Type: text/plain; charset=utf-8
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On 2/6/20 9:41 AM, Neil Armstrong wrote:
> From: Maxime Jourdan <mjourdan@baylibre.com>
> 
> This adds VP9 decoding for the Amlogic GXL, G12A & SM1 SoCs, using
> the commong "HEVC" HW decoder.
> 
> For G12A & SM1, it uses the IOMMU support from the firmware.
> 
> For 10bit decoding, the firmware can only decode in the proprietary
> Amlogic Framebuffer Compression format, but can output in 8bit NV12
> buffer while writing the decoded frame.
> 
> Signed-off-by: Maxime Jourdan <mjourdan@baylibre.com>
> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
> ---
>  drivers/staging/media/meson/vdec/Makefile     |    2 +-
>  drivers/staging/media/meson/vdec/codec_vp9.c  | 2138 +++++++++++++++++
>  drivers/staging/media/meson/vdec/codec_vp9.h  |   13 +
>  drivers/staging/media/meson/vdec/hevc_regs.h  |    7 +
>  drivers/staging/media/meson/vdec/vdec.c       |    5 +
>  .../staging/media/meson/vdec/vdec_helpers.c   |    4 +
>  .../staging/media/meson/vdec/vdec_platform.c  |   38 +
>  7 files changed, 2206 insertions(+), 1 deletion(-)
>  create mode 100644 drivers/staging/media/meson/vdec/codec_vp9.c
>  create mode 100644 drivers/staging/media/meson/vdec/codec_vp9.h
> 
> diff --git a/drivers/staging/media/meson/vdec/Makefile b/drivers/staging/media/meson/vdec/Makefile
> index f55b6e625034..6e726af84ac9 100644
> --- a/drivers/staging/media/meson/vdec/Makefile
> +++ b/drivers/staging/media/meson/vdec/Makefile
> @@ -3,6 +3,6 @@
>  
>  meson-vdec-objs = esparser.o vdec.o vdec_helpers.o vdec_platform.o
>  meson-vdec-objs += vdec_1.o vdec_hevc.o
> -meson-vdec-objs += codec_mpeg12.o codec_h264.o codec_hevc_common.o
> +meson-vdec-objs += codec_mpeg12.o codec_h264.o codec_hevc_common.o codec_vp9.o
>  
>  obj-$(CONFIG_VIDEO_MESON_VDEC) += meson-vdec.o
> diff --git a/drivers/staging/media/meson/vdec/codec_vp9.c b/drivers/staging/media/meson/vdec/codec_vp9.c
> new file mode 100644
> index 000000000000..e7ffbc6dd892
> --- /dev/null
> +++ b/drivers/staging/media/meson/vdec/codec_vp9.c
> @@ -0,0 +1,2138 @@

...

> +#define ROUND_POWER_OF_TWO(value, num) (((value) + (1 << ((num) - 1))) >> (num))

Checkpatch says:

CHECK: Macro argument reuse 'num' - possible side-effects?
#377: FILE: drivers/staging/media/meson/vdec/codec_vp9.c:330:
+#define ROUND_POWER_OF_TWO(value, num) (((value) + (1 << ((num) - 1))) >> (num))

While num is const in this source, I do prefer if this is turned into a static inline.

It's just safer.

Regards,

	Hans