On 20/08/2024 14:48, Thomas Zimmermann wrote:
Hi
Am 20.08.24 um 11:07 schrieb Jocelyn Falempe:
The colors are inverted when testing a s390x VM on a s390x host.
Changing the conversion from DRM_FORMAT -> VIRTIO_GPU_FORMAT on big
endian guests fixes the colors. But it may break big-endian guest on
little-endian host. In this case, the fix should be in qemu, because
the host endianess is not known in the guest VM.
Signed-off-by: Jocelyn Falempe <jfalempe@xxxxxxxxxx>
Acked-by: Javier Martinez Canillas <javierm@xxxxxxxxxx>
---
drivers/gpu/drm/virtio/virtgpu_plane.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/virtio/virtgpu_plane.c
b/drivers/gpu/drm/virtio/virtgpu_plane.c
index 860b5757ec3fc..0ec6ecc96eb13 100644
--- a/drivers/gpu/drm/virtio/virtgpu_plane.c
+++ b/drivers/gpu/drm/virtio/virtgpu_plane.c
@@ -37,16 +37,24 @@ static const uint32_t virtio_gpu_cursor_formats[] = {
DRM_FORMAT_ARGB8888,
};
+#ifdef __BIG_ENDIAN
+#define VIRTIO_GPU_HOST_XRGB8888 VIRTIO_GPU_FORMAT_X8R8G8B8_UNORM
+#define VIRTIO_GPU_HOST_ARGB8888 VIRTIO_GPU_FORMAT_A8R8G8B8_UNORM
+#else
+#define VIRTIO_GPU_HOST_XRGB8888 VIRTIO_GPU_FORMAT_B8G8R8X8_UNORM
+#define VIRTIO_GPU_HOST_ARGB8888 VIRTIO_GPU_FORMAT_B8G8R8A8_UNORM
+#endif
As these defines are only used here, would it be beneficial to put the
__BIG_ENDIAN branch directly around the switch statement?
That was my first version, but I found it difficult to read, when I mix
#ifdef in a switch case.
or maybe something like the following would be better ?
switch (drm_fourcc) {
#ifdef _BIG_ENDIAN
case DRM_FORMAT_XRGB8888:
format = VIRTIO_GPU_FORMAT_X8R8G8B8_UNORM;
break;
case DRM_FORMAT_ARGB8888:
format = VIRTIO_GPU_FORMAT_A8R8G8B8_UNORM;
break;
#else
case DRM_FORMAT_XRGB8888:
format = VIRTIO_GPU_FORMAT_B8G8R8X8_UNORM;
break;
case DRM_FORMAT_ARGB8888:
format = VIRTIO_GPU_FORMAT_B8G8R8A8_UNORM;
break;
#endif
Best regards
Thomas
+
uint32_t virtio_gpu_translate_format(uint32_t drm_fourcc)
{
uint32_t format;
switch (drm_fourcc) {
case DRM_FORMAT_XRGB8888:
- format = VIRTIO_GPU_FORMAT_B8G8R8X8_UNORM;
+ format = VIRTIO_GPU_HOST_XRGB8888;
break;
case DRM_FORMAT_ARGB8888:
- format = VIRTIO_GPU_FORMAT_B8G8R8A8_UNORM;
+ format = VIRTIO_GPU_HOST_ARGB8888;
break;
default:
/*
