At present U-Boot flushes the cache after every character written to ths display. This makes the command-line slower, to the point that pasting in long strings can fail.

Add a cyclic function to sync the display every 10ms. Enable this by default.

Allow much longer times for sandbox, since the SDL display is quite slow.

Avoid size growth if the feature is disabled by making the new init and destroy functions dependent on CYCLIC being enabled.

Signed-off-by: Simon Glass sjg@chromium.org ---

Changes in v2: - Expand help for CONFIG_VIDEO

drivers/video/Kconfig | 35 +++++++++++++++++++++++++++ drivers/video/video-uclass.c | 46 ++++++++++++++++++++++++++++++++---- 2 files changed, 77 insertions(+), 4 deletions(-)

diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig index 6f319ba0d544..ccbfcbcfd824 100644 --- a/drivers/video/Kconfig +++ b/drivers/video/Kconfig @@ -7,6 +7,7 @@ menu "Graphics support" config VIDEO bool "Enable driver model support for LCD/video" depends on DM + imply CYCLIC help This enables driver model for LCD and video devices. These support a bitmap display of various sizes and depths which can be drawn on @@ -14,6 +15,11 @@ config VIDEO option compiles in the video uclass and routes all LCD/video access through this.

+ If CYCLIC is enabled (which it is by default), the cyclic subsystem + is used to flush pending output to the display periodically, rather + than this happening with every chunk of output. This allows for more + efficient operation and faster display output. + if VIDEO

config VIDEO_FONT_4X6 @@ -231,6 +237,35 @@ config NO_FB_CLEAR loads takes over the screen. This, for example, can be used to keep splash image on screen until grub graphical boot menu starts.

+config VIDEO_SYNC_MS + int "Video-sync period in milliseconds for foreground processing" + default 300 if SANDBOX + default 100 + help + This sets the requested, maximum time before a video sync will take + place, in milliseconds. Note that the time between video syncs + may be longer than this, since syncs only happen when the video system + is used, e.g. by outputting a character to the console. + + It may also be shorter, since the video uclass will automatically + force a sync in certain situations. + + Many video-output systems require a sync operation before any output + is visible. This may flush the CPU cache or perhaps copy the + display contents to a hardware framebuffer. Without this, change to + the video may never be displayed. + +config VIDEO_SYNC_CYCLIC_MS + int "Video-sync period in milliseconds for cyclic processing" + depends on CYCLIC + default 100 if SANDBOX + default 10 + help + This sets the frequency of cyclic video syncs. The cyclic system is + used to ensure that when U-Boot is idle, it syncs the video. This + improves the responsiveness of the command line to new characters + being entered. + config PANEL bool "Enable panel uclass support" default y diff --git a/drivers/video/video-uclass.c b/drivers/video/video-uclass.c index 600e12b802d1..fbed4ce861b4 100644 --- a/drivers/video/video-uclass.c +++ b/drivers/video/video-uclass.c @@ -9,6 +9,7 @@ #include <bloblist.h> #include <console.h> #include <cpu_func.h> +#include <cyclic.h> #include <dm.h> #include <log.h> #include <malloc.h> @@ -53,6 +54,8 @@ */ DECLARE_GLOBAL_DATA_PTR;

+struct cyclic_info; + /** * struct video_uc_priv - Information for the video uclass * @@ -61,9 +64,11 @@ DECLARE_GLOBAL_DATA_PTR; * available address to use for a device's framebuffer. It starts at * gd->video_top and works downwards, running out of space when it hits * gd->video_bottom. + * @cyc: handle for cyclic-execution function, or NULL if none */ struct video_uc_priv { ulong video_ptr; + struct cyclic_info *cyc; };

/** struct vid_rgb - Describes a video colour */ @@ -364,6 +369,10 @@ int video_sync(struct udevice *vid, bool force) return ret; }

+ if (CONFIG_IS_ENABLED(CYCLIC) && !force && + get_timer(priv->last_sync) < CONFIG_VIDEO_SYNC_MS) + return 0; + /* * flush_dcache_range() is declared in common.h but it seems that some * architectures do not actually implement it. Is there a way to find @@ -376,11 +385,10 @@ int video_sync(struct udevice *vid, bool force) CONFIG_SYS_CACHELINE_SIZE)); } #elif defined(CONFIG_VIDEO_SANDBOX_SDL) - if (force || get_timer(priv->last_sync) > 100) { - sandbox_sdl_sync(priv->fb); - priv->last_sync = get_timer(0); - } + sandbox_sdl_sync(priv->fb); #endif + priv->last_sync = get_timer(0); + return 0; }

@@ -525,10 +533,16 @@ int video_default_font_height(struct udevice *dev) return vc_priv->y_charsize; }

+static void video_idle(void *ctx) +{ + video_sync_all(); +} + /* Set up the display ready for use */ static int video_post_probe(struct udevice *dev) { struct video_uc_plat *plat = dev_get_uclass_plat(dev); + struct video_uc_priv *uc_priv = uclass_get_priv(dev->uclass); struct video_priv *priv = dev_get_uclass_priv(dev); char name[30], drv[15], *str; const char *drv_name = drv; @@ -599,6 +613,17 @@ static int video_post_probe(struct udevice *dev) } }

+ /* register cyclic as soon as the first video device is probed */ + if (CONFIG_IS_ENABLED(CYCLIC) && (gd->flags && GD_FLG_RELOC) && + !uc_priv->cyc) { + uint ms = CONFIG_IF_ENABLED_INT(CYCLIC, VIDEO_SYNC_CYCLIC_MS); + + uc_priv->cyc = cyclic_register(video_idle, ms * 1000, + "video_init", NULL); + if (!uc_priv->cyc) + return log_msg_ret("cyc", -ENOMEM); + } + return 0; };

@@ -638,6 +663,18 @@ static int video_post_bind(struct udevice *dev) return 0; }

+__maybe_unused static int video_destroy(struct uclass *uc) +{ + struct video_uc_priv *uc_priv = uclass_get_priv(uc); + + if (uc_priv->cyc) { + cyclic_unregister(uc_priv->cyc); + uc_priv->cyc = NULL; + } + + return 0; +} + UCLASS_DRIVER(video) = { .id = UCLASS_VIDEO, .name = "video", @@ -647,4 +684,5 @@ UCLASS_DRIVER(video) = { .priv_auto = sizeof(struct video_uc_priv), .per_device_auto = sizeof(struct video_priv), .per_device_plat_auto = sizeof(struct video_uc_plat), + CONFIG_IS_ENABLED(CYCLIC, (.destroy = video_destroy, )) };

Now that sandbox is using cyclic for video, it trips the 1us time limit. Updating the sandbox display often takes 20ms or more.

Increase the limit to 100ms to avoid a warning.

Signed-off-by: Simon Glass sjg@chromium.org ---

(no changes since v1)

common/Kconfig | 1 + 1 file changed, 1 insertion(+)

diff --git a/common/Kconfig b/common/Kconfig index 5906a4af7c33..f3f6f495adfb 100644 --- a/common/Kconfig +++ b/common/Kconfig @@ -636,6 +636,7 @@ config SPL_CYCLIC

config CYCLIC_MAX_CPU_TIME_US int "Sets the max allowed time for a cyclic function in us" + default 100000 if SANDBOX # sandbox video is quite slow default 1000 help The max allowed time for a cyclic function in us. If a functions