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Message-ID: <ac30786b-dbeb-db77-4fd8-6fe1efbdb929@molgen.mpg.de>
Date:   Tue, 9 Nov 2021 12:22:37 +0100
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Subject: Re: [PATCH] media: aspeed: Fix incorrect resolution detected
Content-Language: en-US
To:     Jammy Huang <jammy_huang@aspeedtech.com>
References: <20211109095453.12363-1-jammy_huang@aspeedtech.com>
Cc:     eajames@linux.ibm.com, mchehab@kernel.org, joel@jms.id.au,
        andrew@aj.id.au, linux-media@vger.kernel.org,
        openbmc@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org,
        linux-aspeed@lists.ozlabs.org, linux-kernel@vger.kernel.org
From:   Paul Menzel <pmenzel@molgen.mpg.de>
In-Reply-To: <20211109095453.12363-1-jammy_huang@aspeedtech.com>
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Dear Jammy,


Am 09.11.21 um 10:54 schrieb Jammy Huang:
> During the process of os-installation, detected resolution's height
> could be less than the correct one.

Can you please elaborate? What OS? What resolution was and what 
resolution should have been detected?

> Increase min-required-count of stable signal to fix the problem.

So you do two changes in the patch? First use the bitfield access 
macros, and then change VE_MODE_DT_HOR_STABLE and VE_MODE_DT_VER_STABLE 
from 6 to 10? Is that the amount of iterations? Why 10 and not 20?

How much time do four iterations add?

Sorry for my ignorance, but if you could make it two patches, that’d be 
great.

> Fixes: d2b4387f3bdf ("media: platform: Add Aspeed Video Engine driver")
> Signed-off-by: Jammy Huang <jammy_huang@aspeedtech.com>
> ---
>   drivers/media/platform/aspeed-video.c | 13 ++++++++++++-
>   1 file changed, 12 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/media/platform/aspeed-video.c b/drivers/media/platform/aspeed-video.c
> index 5da52646b298..625a77ddb479 100644
> --- a/drivers/media/platform/aspeed-video.c
> +++ b/drivers/media/platform/aspeed-video.c
> @@ -196,6 +196,12 @@
>   #define  VE_INTERRUPT_VSYNC_DESC	BIT(11)
>   
>   #define VE_MODE_DETECT			0x30c
> +#define  VE_MODE_DT_HOR_TOLER		GENMASK(31, 28)
> +#define  VE_MODE_DT_VER_TOLER		GENMASK(27, 24)
> +#define  VE_MODE_DT_HOR_STABLE		GENMASK(23, 20)
> +#define  VE_MODE_DT_VER_STABLE		GENMASK(19, 16)
> +#define  VE_MODE_DT_EDG_THROD		GENMASK(15, 8)
> +
>   #define VE_MEM_RESTRICT_START		0x310
>   #define VE_MEM_RESTRICT_END		0x314
>   
> @@ -1199,7 +1205,12 @@ static void aspeed_video_init_regs(struct aspeed_video *video)
>   	aspeed_video_write(video, VE_SCALING_FILTER3, 0x00200000);
>   
>   	/* Set mode detection defaults */
> -	aspeed_video_write(video, VE_MODE_DETECT, 0x22666500);
> +	aspeed_video_write(video, VE_MODE_DETECT,
> +			   FIELD_PREP(VE_MODE_DT_HOR_TOLER, 2) |
> +			   FIELD_PREP(VE_MODE_DT_VER_TOLER, 2) |
> +			   FIELD_PREP(VE_MODE_DT_HOR_STABLE, 10) |
> +			   FIELD_PREP(VE_MODE_DT_VER_STABLE, 10) |
> +			   FIELD_PREP(VE_MODE_DT_EDG_THROD, 0x65));
>   
>   	aspeed_video_write(video, VE_BCD_CTRL, 0);
>   }
> 


Kind regards,

Paul