diff options
| -rw-r--r-- | drivers/gpu/drm/mgag200/mgag200_mode.c | 27 |
1 files changed, 24 insertions, 3 deletions
diff --git a/drivers/gpu/drm/mgag200/mgag200_mode.c b/drivers/gpu/drm/mgag200/mgag200_mode.c index 0326989..e8e20c6 100644 --- a/drivers/gpu/drm/mgag200/mgag200_mode.c +++ b/drivers/gpu/drm/mgag200/mgag200_mode.c @@ -654,12 +654,26 @@ static void mga_g200wb_commit(struct drm_crtc *crtc) WREG_DAC(MGA1064_GEN_IO_DATA, tmp); } - +/* + This is how the framebuffer base address is stored in g200 cards: + * Assume @offset is the gpu_addr variable of the framebuffer object + * Then addr is the number of _pixels_ (not bytes) from the start of + VRAM to the first pixel we want to display. (divided by 2 for 32bit + framebuffers) + * addr is stored in the CRTCEXT0, CRTCC and CRTCD registers + addr<20> -> CRTCEXT0<6> + addr<19-16> -> CRTCEXT0<3-0> + addr<15-8> -> CRTCC<7-0> + addr<7-0> -> CRTCD<7-0> + CRTCEXT0 has to be programmed last to trigger an update and make the + new addr variable take effect. + */ void mga_set_start_address(struct drm_crtc *crtc, unsigned offset) { struct mga_device *mdev = crtc->dev->dev_private; u32 addr; int count; + u8 crtcext0; while (RREG8(0x1fda) & 0x08); while (!(RREG8(0x1fda) & 0x08)); @@ -667,10 +681,17 @@ void mga_set_start_address(struct drm_crtc *crtc, unsigned offset) count = RREG8(MGAREG_VCOUNT) + 2; while (RREG8(MGAREG_VCOUNT) < count); - addr = offset >> 2; + WREG8(MGAREG_CRTCEXT_INDEX, 0); + crtcext0 = RREG8(MGAREG_CRTCEXT_DATA); + crtcext0 &= 0xB0; + addr = offset / 8; + /* Can't store addresses any higher than that... + but we also don't have more than 16MB of memory, so it should be fine. */ + WARN_ON(addr > 0x1fffff); + crtcext0 |= (!!(addr & (1<<20)))<<6; WREG_CRT(0x0d, (u8)(addr & 0xff)); WREG_CRT(0x0c, (u8)(addr >> 8) & 0xff); - WREG_CRT(0xaf, (u8)(addr >> 16) & 0xf); + WREG_ECRT(0x0, ((u8)(addr >> 16) & 0xf) | crtcext0); } |
