[28/65] drm/mgag200: Fix framebuffer base address programming

Steven Rostedt
2013-06-03T22:20:41Z

[-- Attachment #1: 0028-drm-mgag200-Fix-framebuffer-base-address-programming.patch --]
[-- Type: text/plain, Size: 2743 bytes --]

3.6.11.5 stable review patch.
If anyone has any objections, please let me know.

------------------

From: Christopher Harvey <charvey@matrox.com>

[ Upstream commit 9f1d036648c1c5ed81b0e98d7a06d55df972701e ]

Higher bits of the base address of framebuffers weren't being
programmed properly. This caused framebuffers that didn't happen to be
allocated at a low enough address to not be displayed properly.

Signed-off-by: Christopher Harvey <charvey@matrox.com>
Signed-off-by: Mathieu Larouche <mathieu.larouche@matrox.com>
Acked-by: Julia Lemire <jlemire@matrox.com>
Tested-by: Julia Lemire <jlemire@matrox.com>
Cc: stable@vger.kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
drivers/gpu/drm/mgag200/mgag200_mode.c | 27 ++++++++++++++++++++++++---
1 file changed, 24 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/mgag200/mgag200_mode.c b/drivers/gpu/drm/mgag200/mgag200_mode.c
index 26518cc..85ef6cc 100644
--- a/drivers/gpu/drm/mgag200/mgag200_mode.c
+++ b/drivers/gpu/drm/mgag200/mgag200_mode.c
@@ -658,12 +658,26 @@ 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));
@@ -671,10 +685,17 @@ 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);
}

--
1.7.10.4