drm/radeon/kms: fix a regression on r7xx AGP due to the HDP flush fix

commit: 812d046915f48236657f02c06d7dc47140e9ceda
drm/radeon/kms/r7xx: add workaround for hw issue with HDP flush
breaks on AGP boards since there is no VRAM gart table.

This patch fixes the issue by creating a VRAM scratch page so that
can be used on both AGP and PCIE.

Fixes:
https://bugs.freedesktop.org/show_bug.cgi?id=29834

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
index 3dfcfa3ca425..e90d9e3765b4 100644
--- a/drivers/gpu/drm/radeon/radeon.h
+++ b/drivers/gpu/drm/radeon/radeon.h
@@ -1013,6 +1013,11 @@ int radeon_gem_set_tiling_ioctl(struct drm_device *dev, void *data,
 int radeon_gem_get_tiling_ioctl(struct drm_device *dev, void *data,
                                 struct drm_file *filp);
 
+/* VRAM scratch page for HDP bug */
+struct r700_vram_scratch {
+        struct radeon_bo                *robj;
+        volatile uint32_t               *ptr;
+};
 
 /*
  * Core structure, functions and helpers.
@@ -1079,6 +1084,7 @@ struct radeon_device {
         const struct firmware *pfp_fw;  /* r6/700 PFP firmware */
         const struct firmware *rlc_fw;  /* r6/700 RLC firmware */
         struct r600_blit r600_blit;
+        struct r700_vram_scratch vram_scratch;
         int msi_enabled; /* msi enabled */
         struct r600_ih ih; /* r6/700 interrupt ring */
         struct workqueue_struct *wq;