On Mon, May 20, 2019 at 02:33:10PM +0530, Jagan Teki wrote: > The current code is computing vertical video start delay as > > delay = mode->vtotal - (mode->vsync_end - mode->vdisplay) + start; > > On which the second parameter > > mode->vsync_end - mode->vdisplay = front porch + sync timings > > according to "DRM kernel-internal display mode structure" in > include/drm/drm_modes.h > > With adding additional sync timings, the desired video start delay > value as 510 for "bananapi,s070wv20-ct16" panel timings which indeed > trigger panel flip_done timed out as: > > WARNING: CPU: 0 PID: 31 at drivers/gpu/drm/drm_atomic_helper.c:1429 drm_atomic_helper_wait_for_vblanks.part.1+0x298/0x2a0 > [CRTC:46:crtc-0] vblank wait timed out > Modules linked in: > CPU: 0 PID: 31 Comm: kworker/0:1 Not tainted 5.1.0-next-20190514-00029-g09e5b0ed0a58 #18 > Hardware name: Allwinner sun8i Family > Workqueue: events deferred_probe_work_func > [<c010ed54>] (unwind_backtrace) from [<c010b76c>] (show_stack+0x10/0x14) > [<c010b76c>] (show_stack) from [<c0688c70>] (dump_stack+0x84/0x98) > [<c0688c70>] (dump_stack) from [<c011d9e4>] (__warn+0xfc/0x114) > [<c011d9e4>] (__warn) from [<c011da40>] (warn_slowpath_fmt+0x44/0x68) > [<c011da40>] (warn_slowpath_fmt) from [<c040cd50>] (drm_atomic_helper_wait_for_vblanks.part.1+0x298/0x2a0) > [<c040cd50>] (drm_atomic_helper_wait_for_vblanks.part.1) from [<c040e694>] (drm_atomic_helper_commit_tail_rpm+0x5c/0x6c) > [<c040e694>] (drm_atomic_helper_commit_tail_rpm) from [<c040e4dc>] (commit_tail+0x40/0x6c) > [<c040e4dc>] (commit_tail) from [<c040e5cc>] (drm_atomic_helper_commit+0xbc/0x128) > [<c040e5cc>] (drm_atomic_helper_commit) from [<c0411b64>] (restore_fbdev_mode_atomic+0x1cc/0x1dc) > [<c0411b64>] (restore_fbdev_mode_atomic) from [<c04156f8>] (drm_fb_helper_restore_fbdev_mode_unlocked+0x54/0xa0) > [<c04156f8>] (drm_fb_helper_restore_fbdev_mode_unlocked) from [<c0415774>] (drm_fb_helper_set_par+0x30/0x54) > [<c0415774>] (drm_fb_helper_set_par) from [<c03ad450>] (fbcon_init+0x560/0x5ac) > [<c03ad450>] (fbcon_init) from [<c03eb8a0>] (visual_init+0xbc/0x104) > [<c03eb8a0>] (visual_init) from [<c03ed1b8>] (do_bind_con_driver+0x1b0/0x390) > [<c03ed1b8>] (do_bind_con_driver) from [<c03ed780>] (do_take_over_console+0x13c/0x1c4) > [<c03ed780>] (do_take_over_console) from [<c03ad800>] (do_fbcon_takeover+0x74/0xcc) > [<c03ad800>] (do_fbcon_takeover) from [<c013c9c8>] (notifier_call_chain+0x44/0x84) > [<c013c9c8>] (notifier_call_chain) from [<c013cd20>] (__blocking_notifier_call_chain+0x48/0x60) > [<c013cd20>] (__blocking_notifier_call_chain) from [<c013cd50>] (blocking_notifier_call_chain+0x18/0x20) > [<c013cd50>] (blocking_notifier_call_chain) from [<c03a6e44>] (register_framebuffer+0x1e0/0x2f8) > [<c03a6e44>] (register_framebuffer) from [<c04153c0>] (__drm_fb_helper_initial_config_and_unlock+0x2fc/0x50c) > [<c04153c0>] (__drm_fb_helper_initial_config_and_unlock) from [<c04158c8>] (drm_fbdev_client_hotplug+0xe8/0x1b8) > [<c04158c8>] (drm_fbdev_client_hotplug) from [<c0415a20>] (drm_fbdev_generic_setup+0x88/0x118) > [<c0415a20>] (drm_fbdev_generic_setup) from [<c043f060>] (sun4i_drv_bind+0x128/0x160) > [<c043f060>] (sun4i_drv_bind) from [<c044b598>] (try_to_bring_up_master+0x164/0x1a0) > [<c044b598>] (try_to_bring_up_master) from [<c044b668>] (__component_add+0x94/0x140) > [<c044b668>] (__component_add) from [<c0445e1c>] (sun6i_dsi_probe+0x144/0x234) > [<c0445e1c>] (sun6i_dsi_probe) from [<c0452ef4>] (platform_drv_probe+0x48/0x9c) > [<c0452ef4>] (platform_drv_probe) from [<c04512cc>] (really_probe+0x1dc/0x2c8) > [<c04512cc>] (really_probe) from [<c0451518>] (driver_probe_device+0x60/0x160) > [<c0451518>] (driver_probe_device) from [<c044f7a4>] (bus_for_each_drv+0x74/0xb8) > [<c044f7a4>] (bus_for_each_drv) from [<c045107c>] (__device_attach+0xd0/0x13c) > [<c045107c>] (__device_attach) from [<c0450474>] (bus_probe_device+0x84/0x8c) > [<c0450474>] (bus_probe_device) from [<c0450900>] (deferred_probe_work_func+0x64/0x90) > [<c0450900>] (deferred_probe_work_func) from [<c0135970>] (process_one_work+0x204/0x420) > [<c0135970>] (process_one_work) from [<c013690c>] (worker_thread+0x274/0x5a0) > [<c013690c>] (worker_thread) from [<c013b3d8>] (kthread+0x11c/0x14c) > [<c013b3d8>] (kthread) from [<c01010e8>] (ret_from_fork+0x14/0x2c) > Exception stack(0xde539fb0 to 0xde539ff8) > 9fa0: 00000000 00000000 00000000 00000000 > 9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 > 9fe0: 00000000 00000000 00000000 00000000 00000013 00000000 > ---[ end trace 495200a78b24980e ]--- > random: fast init done > [drm:drm_atomic_helper_wait_for_dependencies] *ERROR* [CRTC:46:crtc-0] flip_done timed out > [drm:drm_atomic_helper_wait_for_dependencies] *ERROR* [CONNECTOR:48:DSI-1] flip_done timed out > [drm:drm_atomic_helper_wait_for_dependencies] *ERROR* [PLANE:30:plane-0] flip_done timed out > > But the expected video start delay value is 513 which states that > the second parameter on the computation is "front porch" value > (no sync timings included). > > This is clearly confirmed from the legacy [1] and new [2] bsp codes > that the second parameter on the video start delay is "front porch" > > Here is the detailed evidence for calculating front porch as per > bsp code. > > vfp = panel->lcd_vt - panel->lcd_y - panel->lcd_vbp > => (panel->lcd_vt) - panel->lcd_y - panel->lcd_vbp > => (tt->ver_front_porch + lcdp->panel_info.lcd_vbp > + lcdp->panel_info.lcd_y) - panel->lcd_y - panel->lcd_vbp > => tt->ver_front_porch The comment on patch 1 still applies on this patch Maxime -- Maxime Ripard, Bootlin Embedded Linux and Kernel engineering https://bootlin.com _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
