start value in video start delay computation done in below commit is as per the legacy bsp drivers/video/sunxi/legacy.. "drm/sun4i: dsi: Change the start delay calculation" (sha1: da676c6aa6413d59ab0a80c97bbc273025e640b2) This existing start delay computation gives start value of 35, 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 Tainted: G W 5.1.0-next-20190514-00025-gf928bc7cc146 #15 Hardware name: Allwinner sun8i Family Workqueue: events deferred_probe_work_func [<c010ed54>] (unwind_backtrace) from [<c010b76c>] (show_stack+0x10/0x14) [<c010b76c>] (show_stack) from [<c0688c90>] (dump_stack+0x84/0x98) [<c0688c90>] (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 [<c0411cb0>] (drm_fb_helper_pan_display+0xac/0x1d0) [<c0411cb0>] (drm_fb_helper_pan_display) from [<c03a4e84>] (fb_pan_display+0xcc/0x134) [<c03a4e84>] (fb_pan_display) from [<c03b1214>] (bit_update_start+0x14/0x30) [<c03b1214>] (bit_update_start) from [<c03afe94>] (fbcon_switch+0x3d8/0x4e0) [<c03afe94>] (fbcon_switch) from [<c03ec930>] (redraw_screen+0x174/0x238) [<c03ec930>] (redraw_screen) from [<c03aceb4>] (fbcon_prepare_logo+0x3c4/0x400) [<c03aceb4>] (fbcon_prepare_logo) from [<c03ad2b8>] (fbcon_init+0x3c8/0x5ac) [<c03ad2b8>] (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 [<c044b5b0>] (try_to_bring_up_master+0x164/0x1a0) [<c044b5b0>] (try_to_bring_up_master) from [<c044b680>] (__component_add+0x94/0x140) [<c044b680>] (__component_add) from [<c0445e1c>] (sun6i_dsi_probe+0x144/0x234) [<c0445e1c>] (sun6i_dsi_probe) from [<c0452f0c>] (platform_drv_probe+0x48/0x9c) [<c0452f0c>] (platform_drv_probe) from [<c04512e4>] (really_probe+0x1dc/0x2c8) [<c04512e4>] (really_probe) from [<c0451530>] (driver_probe_device+0x60/0x160) [<c0451530>] (driver_probe_device) from [<c044f7bc>] (bus_for_each_drv+0x74/0xb8) [<c044f7bc>] (bus_for_each_drv) from [<c0451094>] (__device_attach+0xd0/0x13c) [<c0451094>] (__device_attach) from [<c045048c>] (bus_probe_device+0x84/0x8c) [<c045048c>] (bus_probe_device) from [<c0450918>] (deferred_probe_work_func+0x64/0x90) [<c0450918>] (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 755e10f62b83f396 ]--- Console: switching to colour frame buffer device 100x30 [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 start delay value is 1 which is confirmed from new bsp [2]. The important and unclear note on legacy and new bsp codes [1] [2] is both use similar start computation initially but it later reassign it to 1 in new bsp. Unfortunately we don't have any evidence or documentation for this reassignment to 1 in new bsp, but it is working with all supported panels in A33, A64. So, use the start as per new bsp code since it is working in all the supported panels. [2] https://github.com/BPI-SINOVOIP/BPI-M2M-bsp/blob/master/linux-sunxi/drivers/video/sunxi/disp/de/lowlevel_sun8iw5/de_dsi.c#L807 [1] https://github.com/BPI-SINOVOIP/BPI-M2M-bsp/blob/master/linux-sunxi/drivers/video/sunxi/legacy/disp/de_bsp/de/ebios/de_dsi.c#L682 Signed-off-by: Jagan Teki <jagan@xxxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c index c5bec0096b7c..b3ca85410b2c 100644 --- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c +++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c @@ -364,7 +364,17 @@ static void sun6i_dsi_inst_init(struct sun6i_dsi *dsi, static u16 sun6i_dsi_get_video_start_delay(struct sun6i_dsi *dsi, struct drm_display_mode *mode) { - u16 start = clamp(mode->vtotal - mode->vdisplay - 10, 8, 100); + /** + * Allwinner legacy (drivers/video/sunxi/legacy), + * new (drivers/video/sunxi/disp/de/lowlevel_sun8iw5) bsp drivers + * are evaluating start as: + * + * vtotal - vdisplay - 10 + * + * but the new drivers are reassigning start to 1, which seems to be + * working in all supported panels as of now. + */ + u8 start = 1; u16 delay = mode->vtotal - (mode->vsync_end - mode->vdisplay) + start; if (delay > mode->vtotal) -- 2.18.0.321.gffc6fa0e3 _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
