gpu: ipu-v3: image-convert: disable double buffering if necessary

Double-buffering only works if tile sizes are the same and the resizing
coefficient does not change between tiles, even for non-planar formats.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Acked-by: Steve Longerbeam <slongerbeam@gmail.com>
Tested-by: Steve Longerbeam <slongerbeam@gmail.com>

diff --git a/drivers/gpu/ipu-v3/ipu-image-convert.c b/drivers/gpu/ipu-v3/ipu-image-convert.c
index 91fe8f1..3e73494 100644 (file)
--- a/drivers/gpu/ipu-v3/ipu-image-convert.c
+++ b/drivers/gpu/ipu-v3/ipu-image-convert.c
@@ -1990,6 +1990,7 @@ ipu_image_convert_prepare(struct ipu_soc *ipu, enum ipu_ic_task ic_task,
        struct ipu_image_convert_chan *chan;
        struct ipu_image_convert_ctx *ctx;
        unsigned long flags;
+       unsigned int i;
        bool get_res;
        int ret;
 
@@ -2077,15 +2078,37 @@ ipu_image_convert_prepare(struct ipu_soc *ipu, enum ipu_ic_task ic_task,
         * for every tile, and therefore would have to be updated for
         * each buffer which is not possible. So double-buffering is
         * impossible when either the source or destination images are
-        * a planar format (YUV420, YUV422P, etc.).
+        * a planar format (YUV420, YUV422P, etc.). Further, differently
+        * sized tiles or different resizing coefficients per tile
+        * prevent double-buffering as well.
         */
        ctx->double_buffering = (ctx->num_tiles > 1 &&
                                 !s_image->fmt->planar &&
                                 !d_image->fmt->planar);
+       for (i = 1; i < ctx->num_tiles; i++) {
+               if (ctx->in.tile[i].width != ctx->in.tile[0].width ||
+                   ctx->in.tile[i].height != ctx->in.tile[0].height ||
+                   ctx->out.tile[i].width != ctx->out.tile[0].width ||
+                   ctx->out.tile[i].height != ctx->out.tile[0].height) {
+                       ctx->double_buffering = false;
+                       break;
+               }
+       }
+       for (i = 1; i < ctx->in.num_cols; i++) {
+               if (ctx->resize_coeffs_h[i] != ctx->resize_coeffs_h[0]) {
+                       ctx->double_buffering = false;
+                       break;
+               }
+       }
+       for (i = 1; i < ctx->in.num_rows; i++) {
+               if (ctx->resize_coeffs_v[i] != ctx->resize_coeffs_v[0]) {
+                       ctx->double_buffering = false;
+                       break;
+               }
+       }
 
        if (ipu_rot_mode_is_irt(ctx->rot_mode)) {
                unsigned long intermediate_size = d_image->tile[0].size;
-               unsigned int i;
 
                for (i = 1; i < ctx->num_tiles; i++) {
                        if (d_image->tile[i].size > intermediate_size)