Hi Laurent On 27/10/24 8:10 pm, Laurent Pinchart wrote:
On Sat, Oct 26, 2024 at 09:52:43PM +0200, Xavier Roumegue wrote:Hi Umang, Thanks for the patch, this feature sounds promising. On 10/22/24 8:31 AM, Umang Jain wrote:Currently, vertex maps cannot be updated dynamically while dw100 is streaming. This patch enables the support to update the vertex map dynamically at runtime. To support this functionality, we need to allocate and track two sets of DMA-allocated vertex maps, one for the currently applied map and another for the updated (pending) map. Before the start of next frame, if a new user-supplied vertex map is available, the hardware mapping is changed to use new vertex map, thus enabling the user to update the vertex map at runtime.How do you synchronize the new map with the jobs ? That doesn't seem to be supported by the patch, is it a feature that you don't need ?We should ensure no race occurs when the vertex map is updated multiple times when a frame is processing. Hence, vertex map is never updated to the applied vertex map index in .s_ctrl(). It is always updated on the pending vertex map slot, with `maps_mutex` lock held. `maps_mutex` lock is also held when the pending vertex map is applied to the hardware in dw100_start(). Ability to update the vertex map at runtime, enables abritrary rotations/abritrary/arbitrary/and digital zoom features for the input frames, through the dw100 hardware. Signed-off-by: Umang Jain <umang.jain@xxxxxxxxxxxxxxxx> --- drivers/media/platform/nxp/dw100/dw100.c | 73 ++++++++++++++++++------ 1 file changed, 56 insertions(+), 17 deletions(-) diff --git a/drivers/media/platform/nxp/dw100/dw100.c b/drivers/media/platform/nxp/dw100/dw100.c index 54ebf59df682..42712ccff754 100644 --- a/drivers/media/platform/nxp/dw100/dw100.c +++ b/drivers/media/platform/nxp/dw100/dw100.c @@ -83,6 +83,11 @@ struct dw100_q_data { struct v4l2_rect crop; };+struct dw100_map {+ unsigned int *map; + dma_addr_t map_dma;I would have called the field just 'dma' as it's already qualified by the structure name or the field name in dw100_ctx.+}; + struct dw100_ctx { struct v4l2_fh fh; struct dw100_device *dw_dev; @@ -92,12 +97,14 @@ struct dw100_ctx { struct mutex vq_mutex;/* Look Up Table for pixel remapping */- unsigned int *map; - dma_addr_t map_dma; + struct dw100_map maps[2]; + unsigned int applied_map_id; size_t map_size; unsigned int map_width; unsigned int map_height; bool user_map_is_set; + bool user_map_is_updated; + struct mutex maps_mutex;/* Source and destination queue data */struct dw100_q_data q_data[2]; @@ -308,24 +315,31 @@ static int dw100_create_mapping(struct dw100_ctx *ctx) { u32 *user_map;- if (ctx->map)- dma_free_coherent(&ctx->dw_dev->pdev->dev, ctx->map_size, - ctx->map, ctx->map_dma); + for (unsigned int i = 0; i < 2; i++) {for (unsigned int i = 0; i < ARRAY_SIZE(ctx->maps); i++) { struct dw100_map *map = &ctx->maps[i]; and use map below.+ if (ctx->maps[i].map) + dma_free_coherent(&ctx->dw_dev->pdev->dev, ctx->map_size, + ctx->maps[i].map, ctx->maps[i].map_dma);- ctx->map = dma_alloc_coherent(&ctx->dw_dev->pdev->dev, ctx->map_size,- &ctx->map_dma, GFP_KERNEL); + ctx->maps[i].map = dma_alloc_coherent(&ctx->dw_dev->pdev->dev, ctx->map_size, + &ctx->maps[i].map_dma, GFP_KERNEL);- if (!ctx->map)- return -ENOMEM; + if (!ctx->maps[i].map) + return -ENOMEM; + }user_map = dw100_get_user_map(ctx);- memcpy(ctx->map, user_map, ctx->map_size); + + mutex_lock(&ctx->maps_mutex); + ctx->applied_map_id = 0; + memcpy(ctx->maps[ctx->applied_map_id].map, user_map, ctx->map_size); + mutex_unlock(&ctx->maps_mutex);dev_dbg(&ctx->dw_dev->pdev->dev,"%ux%u %s mapping created (d:%pad-c:%p) for stream %ux%u->%ux%u\n", ctx->map_width, ctx->map_height, ctx->user_map_is_set ? "user" : "identity", - &ctx->map_dma, ctx->map, + &ctx->maps[ctx->applied_map_id].map_dma, + ctx->maps[ctx->applied_map_id].map, ctx->q_data[DW100_QUEUE_SRC].pix_fmt.width, ctx->q_data[DW100_QUEUE_DST].pix_fmt.height, ctx->q_data[DW100_QUEUE_SRC].pix_fmt.width, @@ -336,10 +350,12 @@ static int dw100_create_mapping(struct dw100_ctx *ctx)static void dw100_destroy_mapping(struct dw100_ctx *ctx){ - if (ctx->map) { - dma_free_coherent(&ctx->dw_dev->pdev->dev, ctx->map_size, - ctx->map, ctx->map_dma); - ctx->map = NULL; + for (unsigned int i = 0; i < 2; i++) {for (unsigned int i = 0; i < ARRAY_SIZE(ctx->maps); i++) { struct dw100_map *map = &ctx->maps[i]; and use map below.+ if (ctx->maps[i].map) + dma_free_coherent(&ctx->dw_dev->pdev->dev, ctx->map_size, + ctx->maps[i].map, ctx->maps[i].map_dma); + + ctx->maps[i].map = NULL; } }@@ -350,6 +366,15 @@ static int dw100_s_ctrl(struct v4l2_ctrl *ctrl) switch (ctrl->id) {case V4L2_CID_DW100_DEWARPING_16x16_VERTEX_MAP: + u32 *user_map = ctrl->p_new.p_u32;A warning to fix here.+ unsigned int id; + + mutex_lock(&ctx->maps_mutex); + id = ctx->applied_map_id ? 0 : 1; + memcpy(ctx->maps[id].map, user_map, ctx->map_size); + ctx->user_map_is_updated = true;If you call the control before to start the stream, the dma mapping is not yet done(dw100_create_mapping not yet called). Hence, copying the user map to a NULL pointer.The maps could be allocated in dw100_open() when creating the context. That would likely require moving the initialization of ctx->map_width, ctx->map_height and ctx->map_size as well. The handling of the identity map would probably need to be rewritten too.
The ctx->map_width, ctx->map_height and ctx->map_size would be updated on s_fmt().
I think we can solve the NULL pointer issue by allocating when creating the context (open()), however, it would require updating (re-allocation) again before the map can be memcpy()ed before streaming. Because the map dimensions would have changed.
See dw100_s_fmt() ... dims[0] = dw100_get_n_vertices_from_length(q_data->pix_fmt.width); dims[1] = dw100_get_n_vertices_from_length(q_data->pix_fmt.height); ret = v4l2_ctrl_modify_dimensions(ctrl, dims); ```I checked the v4l2_ctrl_modify_dimensions definition to check if it issues a call v4l2_ctrl_type_ops.init (where the map dimensions are updated for dw100) and it does.
So, I think I will have to introduce allocations in dw100_open() so that NULL pointer issue doesn't occur and let the dma allocation get re-allocated with new dimensions just before stream start.
Also, we do not have to move the ctx->map_width, ctx->height abd ctx->map_size inititlisation, since they are already gets initialised to defaults, on the open() path when v4l2_ctrl_new_custom() is done.
+ mutex_unlock(&ctx->maps_mutex); + ctx->user_map_is_set = true; break; } @@ -655,6 +680,8 @@ static int dw100_open(struct file *file)v4l2_fh_add(&ctx->fh); + mutex_init(&ctx->maps_mutex);+ return 0;err:@@ -675,6 +702,7 @@ static int dw100_release(struct file *file) v4l2_ctrl_handler_free(&ctx->hdl); v4l2_m2m_ctx_release(ctx->fh.m2m_ctx); mutex_destroy(&ctx->vq_mutex); + mutex_destroy(&ctx->maps_mutex); kfree(ctx);return 0;@@ -1453,8 +1481,19 @@ static void dw100_start(struct dw100_ctx *ctx, struct vb2_v4l2_buffer *in_vb, dw100_hw_set_destination(dw_dev, &ctx->q_data[DW100_QUEUE_DST], ctx->q_data[DW100_QUEUE_SRC].fmt, &out_vb->vb2_buf); - dw100_hw_set_mapping(dw_dev, ctx->map_dma, - ctx->map_width, ctx->map_height); + + + mutex_lock(&ctx->maps_mutex); + if (ctx->user_map_is_updated) {The hardware register must unconditionally be updated while starting a new context, as a v4l2 m2m supports multi context operations. Otherwise, you may be running with the user mapping used by the previous context. Moreover, the hardware mapping will not be set in case you use the driver as a simple scaler without user mapping, which causes the process to hang as the run does not start and never completes.+ unsigned int id = ctx->applied_map_id ? 0 : 1; + + dw100_hw_set_mapping(dw_dev, ctx->maps[id].map_dma, + ctx->map_width, ctx->map_height); + ctx->applied_map_id = id; + ctx->user_map_is_updated = false; + } + mutex_unlock(&ctx->maps_mutex); + dw100_hw_enable_irq(dw_dev); dw100_hw_dewarp_start(dw_dev);It sounds as this patch requires a collaborative application for running well. All my simple tests failed. You can test a simple scaler/pixfmt conversion operation with v4l2 utils: v4l2-ctl \ -d 0 \ --set-fmt-video-out width=640,height=480,pixelformat=NV12,field=none \ --set-fmt-video width=640,height=480,pixelformat=NV21,field=none \ --stream-out-pattern 3 \ --set-selection-output\ target=crop,top=0,left=0,width=640,height=480,flags= \ --stream-count 100 \ --stream-mmap \ --stream-out-mmap
