Re: [RFC AFBC 10/12] drm/arm/malidp:- Use the newly introduced malidp_format_get_bpp() instead of relying on cpp for calculating framebuffer size

From: Liviu Dudau <Liviu.Dudau@arm.com>
To: Ayan Halder <Ayan.Halder@arm.com>
Cc: Brian Starkey <Brian.Starkey@arm.com>,
	"malidp@foss.arm.com" <malidp@foss.arm.com>,
	"airlied@linux.ie" <airlied@linux.ie>,
	"dri-devel@lists.freedesktop.org"
	<dri-devel@lists.freedesktop.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"maxime.ripard@bootlin.com" <maxime.ripard@bootlin.com>,
	"sean@poorly.run" <sean@poorly.run>,
	"maarten.lankhorst@linux.intel.com" 
	<maarten.lankhorst@linux.intel.com>,
	"corbet@lwn.net" <corbet@lwn.net>,
	"mchehab+samsung@kernel.org" <mchehab+samsung@kernel.org>,
	"gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>,
	"davem@davemloft.net" <davem@davemloft.net>,
	"akpm@linux-foundation.org" <akpm@linux-foundation.org>,
	"nicolas.ferre@microchip.com" <nicolas.ferre@microchip.com>,
	"arnd@arndb.de" <arnd@arndb.de>,
	"linux-doc@vger.kernel.org" <linux-doc@vger.kernel.org>,
	nd <nd@arm.com>
Subject: Re: [RFC AFBC 10/12] drm/arm/malidp:- Use the newly introduced malidp_format_get_bpp() instead of relying on cpp for calculating framebuffer size
Date: Tue, 4 Dec 2018 17:51:39 +0000	[thread overview]
Message-ID: <20181204175139.GR988@e110455-lin.cambridge.arm.com> (raw)
In-Reply-To: <1543836703-8491-11-git-send-email-ayan.halder@arm.com>

On Mon, Dec 03, 2018 at 11:32:04AM +0000, Ayan Halder wrote:
> Formats like DRM_FORMAT_VUY101010, DRM_FORMAT_YUV420_8BIT and
> DRM_FORMAT_YUV420_10BIT are expressed in bits per pixel as they have a non
> integer value of cpp (thus denoted as '0' in drm_format_info[]). Therefore,
> the calculation of AFBC framebuffer size needs to use malidp_format_get_bpp().
> 
> Signed-off-by: Ayan Kumar halder <ayan.halder@arm.com>

Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>

Best regards,
Liviu

> ---
>  drivers/gpu/drm/arm/malidp_drv.c | 13 ++++++++-----
>  1 file changed, 8 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/gpu/drm/arm/malidp_drv.c b/drivers/gpu/drm/arm/malidp_drv.c
> index 2f0b553..b2b97db 100644
> --- a/drivers/gpu/drm/arm/malidp_drv.c
> +++ b/drivers/gpu/drm/arm/malidp_drv.c
> @@ -297,6 +297,7 @@ malidp_verify_afbc_framebuffer_size(struct drm_device *dev,
>  	struct drm_gem_object *objs = NULL;
>  	u32 afbc_superblock_size = 0, afbc_superblock_height = 0;
>  	u32 afbc_superblock_width = 0, afbc_size = 0;
> +	int bpp = 0;
>  
>  	switch (mode_cmd->modifier[0] & AFBC_SIZE_MASK) {
>  	case AFBC_SIZE_16X16:
> @@ -313,15 +314,17 @@ malidp_verify_afbc_framebuffer_size(struct drm_device *dev,
>  	n_superblocks = (mode_cmd->width / afbc_superblock_width) *
>  		(mode_cmd->height / afbc_superblock_height);
>  
> -	afbc_superblock_size = info->cpp[0] * afbc_superblock_width *
> -		afbc_superblock_height;
> +	bpp = malidp_format_get_bpp(info->format);
> +
> +	afbc_superblock_size = (bpp * afbc_superblock_width * afbc_superblock_height) / BITS_PER_BYTE;
>  
>  	afbc_size = ALIGN(n_superblocks * AFBC_HEADER_SIZE, AFBC_SUPERBLK_ALIGNMENT);
>  	afbc_size += n_superblocks * ALIGN(afbc_superblock_size, AFBC_SUPERBLK_ALIGNMENT);
>  
> -	if (mode_cmd->width * info->cpp[0] != mode_cmd->pitches[0]) {
> -		DRM_DEBUG_KMS("Invalid value of pitch (=%u) should be same as width (=%u) * cpp (=%u)\n",
> -			      mode_cmd->pitches[0], mode_cmd->width, info->cpp[0]);
> +	if ((mode_cmd->width * bpp) != (mode_cmd->pitches[0] * BITS_PER_BYTE)) {
> +		DRM_DEBUG_KMS("Invalid value of (pitch * BITS_PER_BYTE) (=%u) "
> +			      "should be same as width (=%u) * bpp (=%u)\n",
> +			      (mode_cmd->pitches[0] * BITS_PER_BYTE), mode_cmd->width, bpp);
>  		return false;
>  	}
>  
> -- 
> 2.7.4
> 

-- 
====================
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| but they're not |
| giving me the   |
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