Unlike the original, deleted Matrox mga driver, the new mgag200 driver
has the XRGB frame-buffer byte swapped on big-endian "RISC"
systems. Fix by enabling byte swapping "PowerPC" OPMODE for any
__BIG_ENDIAN config.
Fixes: 414c45310625 ("mgag200: initial g200se driver (v2)")
Signed-off-by: René Rebe <[email protected]>
Cc: [email protected]
---
V3: move to func, mask prev reg content
V2: move to atomic_update
V3 was only compile tested, while V1/2 were tested on IBM 43p w/ T2/Linux.
---
drivers/gpu/drm/mgag200/mgag200_mode.c | 24 ++++++++++++++++++++++++
1 file changed, 24 insertions(+)
diff --git a/drivers/gpu/drm/mgag200/mgag200_mode.c
b/drivers/gpu/drm/mgag200/mgag200_mode.c
index 951d715dea30..191037ce1029 100644
--- a/drivers/gpu/drm/mgag200/mgag200_mode.c
+++ b/drivers/gpu/drm/mgag200/mgag200_mode.c
@@ -161,6 +161,29 @@ static void mgag200_set_startadd(struct mga_device *mdev,
WREG_ECRT(0x00, crtcext0);
}
+/*
+ * Set the opmode for the hardware swapper for Big-Endian processor
+ * support for the frame buffer aperture and DMAWIN space.
+ */
+static void mgag200_set_datasiz(struct mga_device *mdev, u32 format)
+{
+#if __BIG_ENDIAN
+ u32 opmode = RREG32(MGAREG_OPMODE);
+ opmode &= ~(GENMASK(17, 16) | GENMASK(9, 8) | GENMASK(3, 2));
+
+ /* Big-endian byte-swapping */
+ switch (format) {
+ case DRM_FORMAT_RGB565:
+ opmode |= 0x10100;
+ break;
+ case DRM_FORMAT_XRGB8888:
+ opmode |= 0x20200;
+ break;
+ }
+ WREG32(MGAREG_OPMODE, opmode);
+#endif
+}
+
void mgag200_init_registers(struct mga_device *mdev)
{
u8 crtc11, misc;
@@ -496,6 +519,7 @@ void mgag200_primary_plane_helper_atomic_update(struct
drm_plane *plane,
struct drm_atomic_helper_damage_iter iter;
struct drm_rect damage;
+ mgag200_set_datasiz(mdev, fb->format->format);
drm_atomic_helper_damage_iter_init(&iter, old_plane_state, plane_state);
drm_atomic_for_each_plane_damage(&iter, &damage) {
mgag200_handle_damage(mdev, shadow_plane_state->data, fb,
&damage);
--
2.52.0
--
René Rebe, ExactCODE GmbH, Berlin, Germany
https://exactco.de • https://t2linux.com • https://patreon.com/renerebe
