drm/i915: Handle untiled planes when computing their offsets

We trim the fb to fit the CRTC by computing the offset of that CRTC to
its nearest tile_row origin. This allows us to use framebuffers that are
larger than the CRTC limits without additional work.

However, we failed to compute the offset for a linear framebuffer
correctly as we treated its x-advance in whole tiles (instead of the
linear increment expected), leaving the CRTC misaligned with its
contents.

Fixes regression from commit c2c75131244507c93f812862fdbd4f3a37139401
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Thu Jul 5 12:17:30 2012 +0200

    drm/i915: adjust framebuffer base address on gen4+

v2: Adjust relative x-coordinate after linear alignment (vsyrjala)
v3: Repaint with pokadots (vsyrjala)

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=61152
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: stable@vger.kernel.org
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

3 files changed, 34 insertions, 22 deletions

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 6eb3882ba9bf..0ff10b3af9ea 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -2001,18 +2001,29 @@ void intel_unpin_fb_obj(struct drm_i915_gem_object *obj)
 
 /* Computes the linear offset to the base tile and adjusts x, y. bytes per pixel
  * is assumed to be a power-of-two. */
-unsigned long intel_gen4_compute_offset_xtiled(int *x, int *y,
-                                               unsigned int bpp,
-                                               unsigned int pitch)
+unsigned long intel_gen4_compute_page_offset(int *x, int *y,
+                                             unsigned int tiling_mode,
+                                             unsigned int cpp,
+                                             unsigned int pitch)
 {
-        int tile_rows, tiles;
+        if (tiling_mode != I915_TILING_NONE) {
+                unsigned int tile_rows, tiles;
 
-        tile_rows = *y / 8;
-        *y %= 8;
-        tiles = *x / (512/bpp);
-        *x %= 512/bpp;
+                tile_rows = *y / 8;
+                *y %= 8;
 
-        return tile_rows * pitch * 8 + tiles * 4096;
+                tiles = *x / (512/cpp);
+                *x %= 512/cpp;
+
+                return tile_rows * pitch * 8 + tiles * 4096;
+        } else {
+                unsigned int offset;
+
+                offset = *y * pitch + *x * cpp;
+                *y = 0;
+                *x = (offset & 4095) / cpp;
+                return offset & -4096;
+        }
 }
 
 static int i9xx_update_plane(struct drm_crtc *crtc, struct drm_framebuffer *fb,
@@ -2089,9 +2100,9 @@ static int i9xx_update_plane(struct drm_crtc *crtc, struct drm_framebuffer *fb,
 
         if (INTEL_INFO(dev)->gen >= 4) {
                 intel_crtc->dspaddr_offset =
-                        intel_gen4_compute_offset_xtiled(&x, &y,
-                                                         fb->bits_per_pixel / 8,
-                                                         fb->pitches[0]);
+                        intel_gen4_compute_page_offset(&x, &y, obj->tiling_mode,
+                                                       fb->bits_per_pixel / 8,
+                                                       fb->pitches[0]);
                 linear_offset -= intel_crtc->dspaddr_offset;
         } else {
                 intel_crtc->dspaddr_offset = linear_offset;
@@ -2182,9 +2193,9 @@ static int ironlake_update_plane(struct drm_crtc *crtc,
 
         linear_offset = y * fb->pitches[0] + x * (fb->bits_per_pixel / 8);
         intel_crtc->dspaddr_offset =
-                intel_gen4_compute_offset_xtiled(&x, &y,
-                                                 fb->bits_per_pixel / 8,
-                                                 fb->pitches[0]);
+                intel_gen4_compute_page_offset(&x, &y, obj->tiling_mode,
+                                               fb->bits_per_pixel / 8,
+                                               fb->pitches[0]);
         linear_offset -= intel_crtc->dspaddr_offset;
 
         DRM_DEBUG_KMS("Writing base %08X %08lX %d %d %d\n",
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 005a91f1f8f5..cba02619ec0f 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -649,9 +649,10 @@ extern void intel_update_sprite_watermarks(struct drm_device *dev, int pipe,
 extern void intel_update_linetime_watermarks(struct drm_device *dev, int pipe,
                          struct drm_display_mode *mode);
 
-extern unsigned long intel_gen4_compute_offset_xtiled(int *x, int *y,
-                                                      unsigned int bpp,
-                                                      unsigned int pitch);
+extern unsigned long intel_gen4_compute_page_offset(int *x, int *y,
+                                                    unsigned int tiling_mode,
+                                                    unsigned int bpp,
+                                                    unsigned int pitch);
 
 extern int intel_sprite_set_colorkey(struct drm_device *dev, void *data,
                                      struct drm_file *file_priv);
diff --git a/drivers/gpu/drm/i915/intel_sprite.c b/drivers/gpu/drm/i915/intel_sprite.c
index d086e48a831a..1b6eb76beb7c 100644
--- a/drivers/gpu/drm/i915/intel_sprite.c
+++ b/drivers/gpu/drm/i915/intel_sprite.c
@@ -122,8 +122,8 @@ ivb_update_plane(struct drm_plane *plane, struct drm_framebuffer *fb,
 
         linear_offset = y * fb->pitches[0] + x * pixel_size;
         sprsurf_offset =
-                intel_gen4_compute_offset_xtiled(&x, &y,
-                                                 pixel_size, fb->pitches[0]);
+                intel_gen4_compute_page_offset(&x, &y, obj->tiling_mode,
+                                               pixel_size, fb->pitches[0]);
         linear_offset -= sprsurf_offset;
 
         /* HSW consolidates SPRTILEOFF and SPRLINOFF into a single SPROFFSET
@@ -295,8 +295,8 @@ ilk_update_plane(struct drm_plane *plane, struct drm_framebuffer *fb,
 
         linear_offset = y * fb->pitches[0] + x * pixel_size;
         dvssurf_offset =
-                intel_gen4_compute_offset_xtiled(&x, &y,
-                                                 pixel_size, fb->pitches[0]);
+                intel_gen4_compute_page_offset(&x, &y, obj->tiling_mode,
+                                               pixel_size, fb->pitches[0]);
         linear_offset -= dvssurf_offset;
 
         if (obj->tiling_mode != I915_TILING_NONE)