pll-video => pll-mipi => tcon0 => tcon0-pixel-clock is the typical MIPI clock topology in Allwinner DSI controller. TCON dotclock driver is computing the desired DCLK divider based on panel pixel clock along with input DCLK min, max divider values from tcon driver and that would eventually set the pll-mipi clock rate. The current code is passing dsi min and max divider value as 4 via tcon driver which would ended-up triggering below vblank wait timed out warning on "bananapi,s070wv20-ct16" panel. 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-20190514-00025-g5186cdf10757-dirty #6 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 [<c044b588>] (try_to_bring_up_master+0x164/0x1a0) [<c044b588>] (try_to_bring_up_master) from [<c044b658>] (__component_add+0x94/0x140) [<c044b658>] (__component_add) from [<c0445e0c>] (sun6i_dsi_probe+0x144/0x234) [<c0445e0c>] (sun6i_dsi_probe) from [<c0452ee4>] (platform_drv_probe+0x48/0x9c) [<c0452ee4>] (platform_drv_probe) from [<c04512bc>] (really_probe+0x1dc/0x2c8) [<c04512bc>] (really_probe) from [<c0451508>] (driver_probe_device+0x60/0x160) [<c0451508>] (driver_probe_device) from [<c044f794>] (bus_for_each_drv+0x74/0xb8) [<c044f794>] (bus_for_each_drv) from [<c045106c>] (__device_attach+0xd0/0x13c) [<c045106c>] (__device_attach) from [<c0450464>] (bus_probe_device+0x84/0x8c) [<c0450464>] (bus_probe_device) from [<c04508f0>] (deferred_probe_work_func+0x64/0x90) [<c04508f0>] (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 4017fea4906ab391 ]--- But accordingly to Allwinner A33, A64 BSP codes [1] [2] this divider is clearly using 'format/lanes' for dsi divider value, dsi_clk.clk_div Which would compute the pll_freq and set a clock rate for it in [3] and [4] respectively. The same issue has reproduced in A33, A64 with 4-lane and 2-lane devices and got fixed with this computation logic 'format/lanes', so this patch using dclk min and max dividers as per BSP. [1] https://github.com/BPI-SINOVOIP/BPI-M2M-bsp/blob/master/linux-sunxi/drivers/video/sunxi/disp/de/disp_lcd.c#L1106 [2] https://github.com/BPI-SINOVOIP/BPI-M64-bsp/blob/master/linux-sunxi/drivers/video/sunxi/disp2/disp/de/lowlevel_sun50iw1/disp_al.c#L213 [3] https://github.com/BPI-SINOVOIP/BPI-M2M-bsp/blob/master/linux-sunxi/drivers/video/sunxi/disp/de/disp_lcd.c#L1127 [4] https://github.com/BPI-SINOVOIP/BPI-M2M-bsp/blob/master/linux-sunxi/drivers/video/sunxi/disp/de/disp_lcd.c#L1161 Tested-by: Merlijn Wajer <merlijn@xxxxxxxxxx> Signed-off-by: Jagan Teki <jagan@xxxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/sun4i/sun4i_tcon.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.c b/drivers/gpu/drm/sun4i/sun4i_tcon.c index 9d8d8124b1f6..8f93121fead4 100644 --- a/drivers/gpu/drm/sun4i/sun4i_tcon.c +++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c @@ -341,8 +341,8 @@ static void sun4i_tcon0_mode_set_cpu(struct sun4i_tcon *tcon, u32 block_space, start_delay; u32 tcon_div; - tcon->dclk_min_div = SUN6I_DSI_TCON_DIV; - tcon->dclk_max_div = SUN6I_DSI_TCON_DIV; + tcon->dclk_min_div = bpp/lanes; + tcon->dclk_max_div = bpp/lanes; sun4i_tcon0_mode_set_common(tcon, mode); -- 2.18.0.321.gffc6fa0e3 _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
