RE: [PATCH 05/10] drm/exynos: Use fbdev DMA helpers

["대인기/Tizen Platform Lab(SR)/삼성전자" <inki.dae@samsung.com>]

Hi,

> -----Original Message-----
> From: Thomas Zimmermann <tzimmermann@suse.de>
> Sent: Wednesday, July 5, 2023 12:50 AM
> To: javierm@redhat.com; maarten.lankhorst@linux.intel.com;
> mripard@kernel.org
> Cc: dri-devel@lists.freedesktop.org; linux-arm-kernel@lists.infradead.org;
> linux-samsung-soc@vger.kernel.org; linux-tegra@vger.kernel.org; linux-
> fbdev@vger.kernel.org; Thomas Zimmermann <tzimmermann@suse.de>; Inki Dae
> <inki.dae@samsung.com>; Seung-Woo Kim <sw0312.kim@samsung.com>; Kyungmin
> Park <kyungmin.park@samsung.com>; Krzysztof Kozlowski
> <krzysztof.kozlowski@linaro.org>; Alim Akhtar <alim.akhtar@samsung.com>
> Subject: [PATCH 05/10] drm/exynos: Use fbdev DMA helpers
> 
> Use fbdev's DMA helpers for fbdev emulation. They drivers previously
> used the I/O-memory helpers, while allocating DMA-able system memory.
> This could (in theory) result in bus errors from accessing the memory
> range.
> 
> This bug has been present since the exynos driver was first added.

Acked-by : Inki Dae <inki.dae@samsung.com>

Thanks,
Inki Dae

> 
> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
> Fixes: 1c248b7d2960 ("DRM: add DRM Driver for Samsung SoC EXYNOS4210.")
> Cc: Inki Dae <inki.dae@samsung.com>
> Cc: Seung-Woo Kim <sw0312.kim@samsung.com>
> Cc: Kyungmin Park <kyungmin.park@samsung.com>
> Cc: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
> Cc: Alim Akhtar <alim.akhtar@samsung.com>
> ---
>  drivers/gpu/drm/exynos/Kconfig            | 2 +-
>  drivers/gpu/drm/exynos/exynos_drm_fbdev.c | 4 ++--
>  2 files changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/exynos/Kconfig
> b/drivers/gpu/drm/exynos/Kconfig
> index 7ca7e1dab52c..661b42ad4873 100644
> --- a/drivers/gpu/drm/exynos/Kconfig
> +++ b/drivers/gpu/drm/exynos/Kconfig
> @@ -7,7 +7,7 @@ config DRM_EXYNOS
>  	select DRM_DISPLAY_HELPER if DRM_EXYNOS_DP
>  	select DRM_KMS_HELPER
>  	select VIDEOMODE_HELPERS
> -	select FB_IO_HELPERS if DRM_FBDEV_EMULATION
> +	select FB_DMA_HELPERS if DRM_FBDEV_EMULATION
>  	select SND_SOC_HDMI_CODEC if SND_SOC
>  	help
>  	  Choose this option if you have a Samsung SoC Exynos chipset.
> diff --git a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
> b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
> index fdf65587f1fe..7ca3424b59ce 100644
> --- a/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
> +++ b/drivers/gpu/drm/exynos/exynos_drm_fbdev.c
> @@ -49,9 +49,9 @@ static void exynos_drm_fb_destroy(struct fb_info *info)
> 
>  static const struct fb_ops exynos_drm_fb_ops = {
>  	.owner		= THIS_MODULE,
> -	__FB_DEFAULT_IO_OPS_RDWR,
> +	__FB_DEFAULT_DMA_OPS_RDWR,
>  	DRM_FB_HELPER_DEFAULT_OPS,
> -	__FB_DEFAULT_IO_OPS_DRAW,
> +	__FB_DEFAULT_DMA_OPS_DRAW,
>  	.fb_mmap        = exynos_drm_fb_mmap,
>  	.fb_destroy	= exynos_drm_fb_destroy,
>  };
> --
> 2.41.0