Removes unnecessary pixelpipe cache Invalidation after in-place color space conversion

src/develop/pixelpipe_hb.c

@@ -1407,18 +1407,8 @@ static gboolean _pixelpipe_process_on_CPU(dt_dev_pixelpipe_t *pipe,
                                       roi_in->width, roi_in->height,
                                       cst_from, cst_to, &input_format->cst,
                                       work_profile);
-  /*  We just have changed the input data if cst_from != cst_to so
-      the cacheline cst does not reflect the module input colorspace any more!
-      Note: in opencl code path this is different as the in-data colorspace conversion
-      is always done in cl_mem and thus does not affect pipecache.
-
-      Possible ways to handle this:
-      1. for now we just invalidate that cacheline so if the pipe is reprocessed we won't
-          use wrong data.
-      2. we should implement code for the pipe cache that modifies the data cst.
-  */
-  if(cst_from != cst_to)
-    dt_dev_pixelpipe_invalidate_cacheline(pipe, input);
+  // input_format points into cache->dsc[k]; dt_ioppr_transform_image_colorspace already
+  // wrote the resulting colorspace back via &input_format->cst, so cache metadata is correct.
 
   if(_pipe_has_shutdown(pipe))
     return TRUE;
@@ -2485,9 +2475,7 @@ static gboolean _dev_pixelpipe_process_rec(dt_dev_pixelpipe_t *pipe,
                                               roi_in.width, roi_in.height,
                                               input_format->cst, cst_to, &input_format->cst,
                                               work_profile);
-          // the cacheline cst does not reflect the module input colorspace any more!
-          // FIXME let's invalidate for now
-          dt_dev_pixelpipe_invalidate_cacheline(pipe, input);
+          // input_format points into cache->dsc[k]; cst already updated via &input_format->cst.
         }
 
         // histogram collection for module