drm/radeon/kms: don't apply 7xx HDP flush workaround on AGP

commit f3886f85cfde578f1d0ba6e40ac5f9d70043923b upstream.

It should be required for all 7xx asics, but seems to cause
problems on some AGP 7xx chips.

Fixes:
https://bugzilla.kernel.org/show_bug.cgi?id=19002

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Reported-and-Tested-by: Duncan <1i5t5.duncan@cox.net>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/gpu/drm/radeon/r600.c b/drivers/gpu/drm/radeon/r600.c
index d4503df333e9d0a1d1b5eef49b036b66bd36d315..bcff15375b08378637777c22d2e00d3e480da65f 100644 (file)
--- a/drivers/gpu/drm/radeon/r600.c
+++ b/drivers/gpu/drm/radeon/r600.c
@@ -878,12 +878,15 @@ void r600_pcie_gart_tlb_flush(struct radeon_device *rdev)
        u32 tmp;
 
        /* flush hdp cache so updates hit vram */
-       if ((rdev->family >= CHIP_RV770) && (rdev->family <= CHIP_RV740)) {
+       if ((rdev->family >= CHIP_RV770) && (rdev->family <= CHIP_RV740) &&
+           !(rdev->flags & RADEON_IS_AGP)) {
                void __iomem *ptr = (void *)rdev->gart.table.vram.ptr;
                u32 tmp;
 
                /* r7xx hw bug.  write to HDP_DEBUG1 followed by fb read
                 * rather than write to HDP_REG_COHERENCY_FLUSH_CNTL
+                * This seems to cause problems on some AGP cards. Just use the old
+                * method for them.
                 */
                WREG32(HDP_DEBUG1, 0);
                tmp = readl((void __iomem *)ptr);
@@ -3525,10 +3528,12 @@ int r600_debugfs_mc_info_init(struct radeon_device *rdev)
 void r600_ioctl_wait_idle(struct radeon_device *rdev, struct radeon_bo *bo)
 {
        /* r7xx hw bug.  write to HDP_DEBUG1 followed by fb read
-        * rather than write to HDP_REG_COHERENCY_FLUSH_CNTL
+        * rather than write to HDP_REG_COHERENCY_FLUSH_CNTL.
+        * This seems to cause problems on some AGP cards. Just use the old
+        * method for them.
         */
        if ((rdev->family >= CHIP_RV770) && (rdev->family <= CHIP_RV740) &&
-           rdev->vram_scratch.ptr) {
+           rdev->vram_scratch.ptr && !(rdev->flags & RADEON_IS_AGP)) {
                void __iomem *ptr = (void *)rdev->vram_scratch.ptr;
                u32 tmp;