drm/tegra: Properly align stride for framebuffers

Tegra20 and Tegra30 both required the buffer line stride to be aligned
on 8 byte boundaries. Tegra114 and Tegra124 increased the alignment to
64 bytes. Introduce a parameter to specify the alignment requirements
for each display controller and round up the pitch of newly allocated
framebuffers appropriately.

Originally-by: Stéphane Marchesin <marcheu@chromium.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>

4 files changed, 27 insertions, 1 deletions

diff --git a/drivers/gpu/drm/tegra/dc.c b/drivers/gpu/drm/tegra/dc.c
index afcca04f5367..8886907d44b0 100644
--- a/drivers/gpu/drm/tegra/dc.c
+++ b/drivers/gpu/drm/tegra/dc.c
@@ -19,6 +19,7 @@ struct tegra_dc_soc_info {
         bool supports_interlacing;
         bool supports_cursor;
         bool supports_block_linear;
+        unsigned int pitch_align;
 };
 
 struct tegra_plane {
@@ -1283,12 +1284,20 @@ static int tegra_dc_init(struct host1x_client *client)
 {
         struct drm_device *drm = dev_get_drvdata(client->parent);
         struct tegra_dc *dc = host1x_client_to_dc(client);
+        struct tegra_drm *tegra = drm->dev_private;
         int err;
 
         drm_crtc_init(drm, &dc->base, &tegra_crtc_funcs);
         drm_mode_crtc_set_gamma_size(&dc->base, 256);
         drm_crtc_helper_add(&dc->base, &tegra_crtc_helper_funcs);
 
+        /*
+         * Keep track of the minimum pitch alignment across all display
+         * controllers.
+         */
+        if (dc->soc->pitch_align > tegra->pitch_align)
+                tegra->pitch_align = dc->soc->pitch_align;
+
         err = tegra_dc_rgb_init(drm, dc);
         if (err < 0 && err != -ENODEV) {
                 dev_err(dc->dev, "failed to initialize RGB output: %d\n", err);
@@ -1347,18 +1356,28 @@ static const struct tegra_dc_soc_info tegra20_dc_soc_info = {
         .supports_interlacing = false,
         .supports_cursor = false,
         .supports_block_linear = false,
+        .pitch_align = 8,
 };
 
 static const struct tegra_dc_soc_info tegra30_dc_soc_info = {
         .supports_interlacing = false,
         .supports_cursor = false,
         .supports_block_linear = false,
+        .pitch_align = 8,
+};
+
+static const struct tegra_dc_soc_info tegra114_dc_soc_info = {
+        .supports_interlacing = false,
+        .supports_cursor = false,
+        .supports_block_linear = false,
+        .pitch_align = 64,
 };
 
 static const struct tegra_dc_soc_info tegra124_dc_soc_info = {
         .supports_interlacing = true,
         .supports_cursor = true,
         .supports_block_linear = true,
+        .pitch_align = 64,
 };
 
 static const struct of_device_id tegra_dc_of_match[] = {
diff --git a/drivers/gpu/drm/tegra/drm.h b/drivers/gpu/drm/tegra/drm.h
index 96d754e7b3eb..e89c70fa82d5 100644
--- a/drivers/gpu/drm/tegra/drm.h
+++ b/drivers/gpu/drm/tegra/drm.h
@@ -45,6 +45,8 @@ struct tegra_drm {
 #ifdef CONFIG_DRM_TEGRA_FBDEV
         struct tegra_fbdev *fbdev;
 #endif
+
+        unsigned int pitch_align;
 };
 
 struct tegra_drm_client;
diff --git a/drivers/gpu/drm/tegra/fb.c b/drivers/gpu/drm/tegra/fb.c
index 7790d43ad082..3513d12d5aa1 100644
--- a/drivers/gpu/drm/tegra/fb.c
+++ b/drivers/gpu/drm/tegra/fb.c
@@ -194,6 +194,7 @@ static int tegra_fbdev_probe(struct drm_fb_helper *helper,
                              struct drm_fb_helper_surface_size *sizes)
 {
         struct tegra_fbdev *fbdev = to_tegra_fbdev(helper);
+        struct tegra_drm *tegra = helper->dev->dev_private;
         struct drm_device *drm = helper->dev;
         struct drm_mode_fb_cmd2 cmd = { 0 };
         unsigned int bytes_per_pixel;
@@ -208,7 +209,8 @@ static int tegra_fbdev_probe(struct drm_fb_helper *helper,
 
         cmd.width = sizes->surface_width;
         cmd.height = sizes->surface_height;
-        cmd.pitches[0] = sizes->surface_width * bytes_per_pixel;
+        cmd.pitches[0] = round_up(sizes->surface_width * bytes_per_pixel,
+                                  tegra->pitch_align);
         cmd.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
                                                      sizes->surface_depth);
 
diff --git a/drivers/gpu/drm/tegra/gem.c b/drivers/gpu/drm/tegra/gem.c
index c1e4e8b6e5ca..2545c7a468a2 100644
--- a/drivers/gpu/drm/tegra/gem.c
+++ b/drivers/gpu/drm/tegra/gem.c
@@ -16,6 +16,7 @@
 #include <linux/dma-buf.h>
 #include <drm/tegra_drm.h>
 
+#include "drm.h"
 #include "gem.h"
 
 static inline struct tegra_bo *host1x_to_tegra_bo(struct host1x_bo *bo)
@@ -259,8 +260,10 @@ int tegra_bo_dumb_create(struct drm_file *file, struct drm_device *drm,
                          struct drm_mode_create_dumb *args)
 {
         int min_pitch = DIV_ROUND_UP(args->width * args->bpp, 8);
+        struct tegra_drm *tegra = drm->dev_private;
         struct tegra_bo *bo;
 
+        min_pitch = round_up(min_pitch, tegra->pitch_align);
         if (args->pitch < min_pitch)
                 args->pitch = min_pitch;