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

Thomas Zimmermann
2023-07-04T16:01:44Z

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.

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