On 2020-09-08 16:16, Stefan Agner wrote:

The lcdif IP does not support a framebuffer pitch (stride) other than framebuffer width. Check for equality and reject the framebuffer otherwise.

This prevents a distorted picture when using 640x800 and running the Mesa graphics stack. Mesa tries to use a cache aligned stride, which leads at that particular resolution to width != stride. Currently Mesa has no fallback behavior, but rejecting this configuration allows userspace to handle the issue correctly.

Fixes: 45d59d704080 ("drm: Add new driver for MXSFB controller") Signed-off-by: Stefan Agner stefan@agner.ch Reviewed-by: Laurent Pinchart laurent.pinchart@ideasonboard.com

Applied to drm-misc-next.

-- Stefan

---

Changes in v3:

• Fix typo in commit message
• Add fixes tag

Changes in v2:

• Validate pitch in fb_create callback

drivers/gpu/drm/mxsfb/mxsfb_drv.c | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/mxsfb/mxsfb_drv.c b/drivers/gpu/drm/mxsfb/mxsfb_drv.c index 8c549c3931af..35122aef037b 100644 --- a/drivers/gpu/drm/mxsfb/mxsfb_drv.c +++ b/drivers/gpu/drm/mxsfb/mxsfb_drv.c @@ -21,6 +21,7 @@ #include <drm/drm_connector.h> #include <drm/drm_drv.h> #include <drm/drm_fb_helper.h> +#include <drm/drm_fourcc.h> #include <drm/drm_gem_cma_helper.h> #include <drm/drm_gem_framebuffer_helper.h> #include <drm/drm_irq.h> @@ -81,8 +82,26 @@ void mxsfb_disable_axi_clk(struct mxsfb_drm_private *mxsfb) clk_disable_unprepare(mxsfb->clk_axi); }

+static struct drm_framebuffer * +mxsfb_fb_create(struct drm_device *dev, struct drm_file *file_priv,

• const struct drm_mode_fb_cmd2 *mode_cmd)
  

+{

• const struct drm_format_info *info;
• info = drm_get_format_info(dev, mode_cmd);
• if (!info)

• return ERR_PTR(-EINVAL);
  

• if (mode_cmd->width * info->cpp[0] != mode_cmd->pitches[0]) {

• dev_dbg(dev->dev, "Invalid pitch: fb width must match pitch\n");
  

• return ERR_PTR(-EINVAL);
  

• }
• return drm_gem_fb_create(dev, file_priv, mode_cmd);

+}

static const struct drm_mode_config_funcs mxsfb_mode_config_funcs = {

• .fb_create = drm_gem_fb_create,

• .fb_create = mxsfb_fb_create, .atomic_check = drm_atomic_helper_check, .atomic_commit = drm_atomic_helper_commit,

};