Subject: Re: [PATCH 1/3] media: cedrus: Properly signal size in mode register

From: Paul Kocialkowski <[email-masked]>
Date: Tue, 5 Nov 2019 09:10:34 +0100

Hi,

On Mon 04 Nov 19, 17:33, Jernej Škrabec wrote:
> Dne ponedeljek, 04. november 2019 ob 11:02:28 CET je Paul Kocialkowski 
> napisal(a):
> > Hi Jernej,
> > 
> > On Sat 26 Oct 19, 09:49, Jernej Skrabec wrote:
> > > Mode register also holds information if video width is bigger than 2048
> > > and if it is equal to 4096.
> > > 
> > > Rework cedrus_engine_enable() to properly signal this properties.
> > 
> > Thanks for the patch, looks good to me!
> > 
> > Acked-by: Paul Kocialkowski <[email-masked]>
> > 
> > One minor thing: maybe we should have a way to set the maximum dimensions
> > depending on the generation of the engine in use and the actual maximum
> > supported by the hardware.
> > 
> > Maybe either as dedicated new fields in struct cedrus_variant or as
> > capability flags.
> 
> I was thinking about first solution, but after going trough manuals, it was 
> unclear what are real limitations. For example, H3 manual states that it is 
> capable of decoding H264 1080p@60Hz. However, I know for a fact that it is 
> also capable of decoding 4k videos, but probably not at 60 Hz. I don't own 
> anything older that A83T, so I don't know what are capabilities of those SoCs. 

So I guess in this case we should try and see. I could try to look into it at
some point in the future too if you're not particulary interested.

> Anyway, being slow is still ok for some tasks, like transcoding, so we can't 
> limit decoding to 1080p just because it's slow. It is probably still faster 
> than doing it in SW. Not to mention that it's still ok for some videos, a lot 
> of them uses 24 fps.

I agree, it's best to expose the maximum supported resolution by the hardware,
even if it means running at a lower fps.

Do you know if we have a way to report some estimation of the maximum supported
fps to userspace? It would be useful to let userspace decide whether it's a
better fit than software decoding.

Cheers,

Paul

> Best regards,
> Jernej
> 
> > 
> > Anyway that can be done later since we were already hardcoding this.
> > 
> > Cheers,
> > 
> > Paul
> > 
> > > Signed-off-by: Jernej Skrabec <[email-masked]>
> > > ---
> > > 
> > >  drivers/staging/media/sunxi/cedrus/cedrus_h264.c  | 2 +-
> > >  drivers/staging/media/sunxi/cedrus/cedrus_h265.c  | 2 +-
> > >  drivers/staging/media/sunxi/cedrus/cedrus_hw.c    | 9 +++++++--
> > >  drivers/staging/media/sunxi/cedrus/cedrus_hw.h    | 2 +-
> > >  drivers/staging/media/sunxi/cedrus/cedrus_mpeg2.c | 2 +-
> > >  drivers/staging/media/sunxi/cedrus/cedrus_regs.h  | 2 ++
> > >  6 files changed, 13 insertions(+), 6 deletions(-)
> > > 
> > > diff --git a/drivers/staging/media/sunxi/cedrus/cedrus_h264.c
> > > b/drivers/staging/media/sunxi/cedrus/cedrus_h264.c index
> > > 7487f6ab7576..d2c854ecdf15 100644
> > > --- a/drivers/staging/media/sunxi/cedrus/cedrus_h264.c
> > > +++ b/drivers/staging/media/sunxi/cedrus/cedrus_h264.c
> > > @@ -485,7 +485,7 @@ static void cedrus_h264_setup(struct cedrus_ctx *ctx,
> > > 
> > >  {
> > >  
> > >  	struct cedrus_dev *dev = ctx->dev;
> > > 
> > > -	cedrus_engine_enable(dev, CEDRUS_CODEC_H264);
> > > +	cedrus_engine_enable(ctx, CEDRUS_CODEC_H264);
> > > 
> > >  	cedrus_write(dev, VE_H264_SDROT_CTRL, 0);
> > >  	cedrus_write(dev, VE_H264_EXTRA_BUFFER1,
> > > 
> > > diff --git a/drivers/staging/media/sunxi/cedrus/cedrus_h265.c
> > > b/drivers/staging/media/sunxi/cedrus/cedrus_h265.c index
> > > 9bc921866f70..6945dc74e1d7 100644
> > > --- a/drivers/staging/media/sunxi/cedrus/cedrus_h265.c
> > > +++ b/drivers/staging/media/sunxi/cedrus/cedrus_h265.c
> > > @@ -276,7 +276,7 @@ static void cedrus_h265_setup(struct cedrus_ctx *ctx,
> > > 
> > >  	}
> > >  	
> > >  	/* Activate H265 engine. */
> > > 
> > > -	cedrus_engine_enable(dev, CEDRUS_CODEC_H265);
> > > +	cedrus_engine_enable(ctx, CEDRUS_CODEC_H265);
> > > 
> > >  	/* Source offset and length in bits. */
> > > 
> > > diff --git a/drivers/staging/media/sunxi/cedrus/cedrus_hw.c
> > > b/drivers/staging/media/sunxi/cedrus/cedrus_hw.c index
> > > 570a9165dd5d..3acfa21bc124 100644
> > > --- a/drivers/staging/media/sunxi/cedrus/cedrus_hw.c
> > > +++ b/drivers/staging/media/sunxi/cedrus/cedrus_hw.c
> > > @@ -30,7 +30,7 @@
> > > 
> > >  #include "cedrus_hw.h"
> > >  #include "cedrus_regs.h"
> > > 
> > > -int cedrus_engine_enable(struct cedrus_dev *dev, enum cedrus_codec codec)
> > > +int cedrus_engine_enable(struct cedrus_ctx *ctx, enum cedrus_codec codec)
> > > 
> > >  {
> > >  
> > >  	u32 reg = 0;
> > > 
> > > @@ -58,7 +58,12 @@ int cedrus_engine_enable(struct cedrus_dev *dev, enum
> > > cedrus_codec codec)> 
> > >  		return -EINVAL;
> > >  	
> > >  	}
> > > 
> > > -	cedrus_write(dev, VE_MODE, reg);
> > > +	if (ctx->src_fmt.width == 4096)
> > > +		reg |= VE_MODE_PIC_WIDTH_IS_4096;
> > > +	if (ctx->src_fmt.width > 2048)
> > > +		reg |= VE_MODE_PIC_WIDTH_MORE_2048;
> > > +
> > > +	cedrus_write(ctx->dev, VE_MODE, reg);
> > > 
> > >  	return 0;
> > >  
> > >  }
> > > 
> > > diff --git a/drivers/staging/media/sunxi/cedrus/cedrus_hw.h
> > > b/drivers/staging/media/sunxi/cedrus/cedrus_hw.h index
> > > 27d0882397aa..604ff932fbf5 100644
> > > --- a/drivers/staging/media/sunxi/cedrus/cedrus_hw.h
> > > +++ b/drivers/staging/media/sunxi/cedrus/cedrus_hw.h
> > > @@ -16,7 +16,7 @@
> > > 
> > >  #ifndef _CEDRUS_HW_H_
> > >  #define _CEDRUS_HW_H_
> > > 
> > > -int cedrus_engine_enable(struct cedrus_dev *dev, enum cedrus_codec
> > > codec);
> > > +int cedrus_engine_enable(struct cedrus_ctx *ctx, enum cedrus_codec
> > > codec);
> > > 
> > >  void cedrus_engine_disable(struct cedrus_dev *dev);
> > >  
> > >  void cedrus_dst_format_set(struct cedrus_dev *dev,
> > > 
> > > diff --git a/drivers/staging/media/sunxi/cedrus/cedrus_mpeg2.c
> > > b/drivers/staging/media/sunxi/cedrus/cedrus_mpeg2.c index
> > > 13c34927bad5..8bcd6b8f9e2d 100644
> > > --- a/drivers/staging/media/sunxi/cedrus/cedrus_mpeg2.c
> > > +++ b/drivers/staging/media/sunxi/cedrus/cedrus_mpeg2.c
> > > @@ -96,7 +96,7 @@ static void cedrus_mpeg2_setup(struct cedrus_ctx *ctx,
> > > struct cedrus_run *run)> 
> > >  	quantization = run->mpeg2.quantization;
> > >  	
> > >  	/* Activate MPEG engine. */
> > > 
> > > -	cedrus_engine_enable(dev, CEDRUS_CODEC_MPEG2);
> > > +	cedrus_engine_enable(ctx, CEDRUS_CODEC_MPEG2);
> > > 
> > >  	/* Set intra quantization matrix. */
> > > 
> > > diff --git a/drivers/staging/media/sunxi/cedrus/cedrus_regs.h
> > > b/drivers/staging/media/sunxi/cedrus/cedrus_regs.h index
> > > 4275a307d282..ace3d49fcd82 100644
> > > --- a/drivers/staging/media/sunxi/cedrus/cedrus_regs.h
> > > +++ b/drivers/staging/media/sunxi/cedrus/cedrus_regs.h
> > > @@ -35,6 +35,8 @@
> > > 
> > >  #define VE_MODE					0x00
> > > 
> > > +#define VE_MODE_PIC_WIDTH_IS_4096		BIT(22)
> > > +#define VE_MODE_PIC_WIDTH_MORE_2048		BIT(21)
> > > 
> > >  #define VE_MODE_REC_WR_MODE_2MB			(0x01 << 20)
> > >  #define VE_MODE_REC_WR_MODE_1MB			(0x00 << 20)
> > >  #define VE_MODE_DDR_MODE_BW_128			(0x03 << 16)
> 
> 
> 
> 

-- 
Paul Kocialkowski, Bootlin
Embedded Linux and kernel engineering
https://bootlin.com
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