DRM: totally broken VOP output mode selector rk3288

[mcerveny]

Hello.

There is totally broken VOP for rk3288 platforms (TinkerBoard, ...). It usually boots only to 800x600 resolution that pass both errors (see also http://tinkerboarding.co.uk/forum/showthread.php?tid=61&pid=323#pid323).
I identified 2 issues in rockchip DRM/kernel but unable to correct:

1) nearly all output modes are blocked for DMT/VESA modes

Problem is in new validity checking (commit 7e3e0c5) and/or modification of "dclk_vop" clock driver (commit d072a98 maybe other). Due to strictly checking available clock in vop_crtc_mode_valid() (see https://github.com/rockchip-linux/kernel/blob/release-4.4/drivers/gpu/drm/rockchip/rockchip_drm_vop.c#L1443) and some modification in "dclk_vop" clock driver it is not possible to set even basic DMT/VESA modes. Mode validation fails with MODE_CLOCK_RANGE. Example (compare clock != request_clock from code):

Modeline 100:"1280x1024" 75 135000 1280 1296 1440 1688 1024 1025 1028 1066 0x40 0x5
clock error: 133333 != 135000
Modeline 80:"1280x1024" 60 108000 1280 1328 1440 1688 1024 1025 1028 1066 0x48 0x5
clock error: 100000 != 108000
Modeline 88:"1024x768" 75 78800 1024 1040 1136 1312 768 769 772 800 0x40 0x5
clock error: 74250 != 78800
Modeline 90:"1024x768" 60 65000 1024 1048 1184 1344 768 771 777 806 0x40 0xa
clock error: 62500 != 65000

2) check modes to "fail-safe" framebuffer size (1024x768) and not to maximum available

The problem is in late hdmi start (state "connected"). Framebuffer is already set do "1024x768" default but new modes are validated to this resolution and not to maximum available (8192x8192?). Mode validation fails with MODE_VIRTUAL_X. Sample from dmesg (XXXX is inside drm_mode_validate_size() "DRM_DEBUG_KMS("XXXX %dx%d %dx%d\n", mode->hdisplay, mode->vdisplay, maxX, maxY);" and "dump_stack()" shows call from drm_fb_helper_hotplug_event() (https://github.com/rockchip-linux/kernel/blob/release-4.4/drivers/gpu/drm/drm_fb_helper.c#L2161) and from rockchip_drm_output_poll_changed() (https://github.com/rockchip-linux/kernel/blob/release-4.4/drivers/gpu/drm/rockchip/rockchip_drm_fb.c#L220)):

[    1.440674] [drm:drm_helper_probe_single_connector_modes_merge_bits] [CONNECTOR:78:HDMI-A-1] disconnected
[    1.440693] rockchip-drm display-subsystem: No connectors reported connected with modes
[    1.448764] [drm:drm_setup_crtcs] 
[    1.448795] [drm:drm_sysfs_hotplug_event] generating hotplug event
[    1.448849] [drm:drm_enable_connectors] connector 78 enabled? no
[    1.448865] [drm:drm_setup_crtcs] picking CRTCs for 8192x8192 config
[    1.448881] [drm:drm_fb_helper_single_fb_probe] Cannot find any crtc or sizes - going 1024x768
[    1.462950] [drm:rockchip_gem_get_pages] rockchip_gem_get_pages, 201, end = 768, n_pages = 768
[    1.467034] [drm:rockchip_drm_fbdev_create] FB [1024x768]-24 kvaddr=f0921000 offset=0 size=3145728
....
[    4.246398] [drm:drm_helper_hpd_irq_event] [CONNECTOR:78:HDMI-A-1] status updated from disconnected to connected
[    4.246411] [drm:drm_sysfs_hotplug_event] generating hotplug event
[    4.246451] [drm:drm_fb_helper_hotplug_event] 
[    4.246467] [drm:drm_helper_probe_single_connector_modes_merge_bits] [CONNECTOR:78:HDMI-A-1]
....
[    4.572432] [drm:drm_mode_validate_size] XXXX 1280x1024 1024x768

Are there any new patches to resolve this issues ?

Thanks, Martin

[wzyy2]

@yueshu

[mcerveny]

Tested with release-20170417, not resolved (dmesg with "drm.debug=0x4" on linux cmdline).

[    3.570313] [drm:drm_mode_debug_printmodeline] Modeline 81:"1280x1024" 60 108000 1280 1328 1440 1688 1024 1025 1028 1066 0x48 0x5
[    3.570319] [drm:drm_mode_prune_invalid] Not using 1280x1024 mode: VIRTUAL_X
[    3.570333] [drm:drm_mode_debug_printmodeline] Modeline 83:"640x480" 0 31500 640 656 720 840 480 481 484 500 0x40 0xa
[    3.570339] [drm:drm_mode_prune_invalid] Not using 640x480 mode: CLOCK_RANGE
[    3.570351] [drm:drm_mode_debug_printmodeline] Modeline 84:"640x480" 0 31500 640 664 704 832 480 489 491 520 0x40 0xa
[    3.570357] [drm:drm_mode_prune_invalid] Not using 640x480 mode: CLOCK_RANGE
[    3.570368] [drm:drm_mode_debug_printmodeline] Modeline 85:"640x480" 0 25200 640 656 752 800 480 490 492 525 0x40 0xa
[    3.570374] [drm:drm_mode_prune_invalid] Not using 640x480 mode: CLOCK_RANGE
[    3.570385] [drm:drm_mode_debug_printmodeline] Modeline 86:"720x400" 0 28320 720 738 846 900 400 412 414 449 0x40 0x6
[    3.570390] [drm:drm_mode_prune_invalid] Not using 720x400 mode: CLOCK_RANGE
[    3.570402] [drm:drm_mode_debug_printmodeline] Modeline 87:"1280x1024" 0 135000 1280 1296 1440 1688 1024 1025 1028 1066 0x40 0x5
[    3.570407] [drm:drm_mode_prune_invalid] Not using 1280x1024 mode: VIRTUAL_X
[    3.570418] [drm:drm_mode_debug_printmodeline] Modeline 88:"1024x768" 0 78800 1024 1040 1136 1312 768 769 772 800 0x40 0x5
[    3.570424] [drm:drm_mode_prune_invalid] Not using 1024x768 mode: CLOCK_RANGE
[    3.570435] [drm:drm_mode_debug_printmodeline] Modeline 89:"1024x768" 0 75000 1024 1048 1184 1328 768 771 777 806 0x40 0xa
[    3.570441] [drm:drm_mode_prune_invalid] Not using 1024x768 mode: CLOCK_RANGE
[    3.570452] [drm:drm_mode_debug_printmodeline] Modeline 90:"1024x768" 0 65000 1024 1048 1184 1344 768 771 777 806 0x40 0xa
[    3.570458] [drm:drm_mode_prune_invalid] Not using 1024x768 mode: CLOCK_RANGE
[    3.570469] [drm:drm_mode_debug_printmodeline] Modeline 91:"832x624" 0 57284 832 864 928 1152 624 625 628 667 0x40 0xa
[    3.570474] [drm:drm_mode_prune_invalid] Not using 832x624 mode: CLOCK_RANGE
[    3.570486] [drm:drm_mode_debug_printmodeline] Modeline 94:"1152x864" 0 108000 1152 1216 1344 1600 864 865 868 900 0x40 0x5
[    3.570492] [drm:drm_mode_prune_invalid] Not using 1152x864 mode: VIRTUAL_X
[    3.570502] [drm:drm_helper_probe_single_connector_modes_merge_bits] [CONNECTOR:78:HDMI-A-1] probed modes :
[    3.570513] [drm:drm_mode_debug_printmodeline] Modeline 92:"800x600" 75 49500 800 816 896 1056 600 601 604 625 0x40 0x5
[    3.570524] [drm:drm_mode_debug_printmodeline] Modeline 93:"800x600" 72 50000 800 856 976 1040 600 637 643 666 0x40 0x5
[    3.570535] [drm:drm_mode_debug_printmodeline] Modeline 82:"800x600" 60 40000 800 840 968 1056 600 601 605 628 0x40 0x5
[    3.570552] [drm:drm_setup_crtcs] 
[    3.570560] [drm:drm_enable_connectors] connector 78 enabled? yes
[    3.570567] [drm:drm_target_preferred] looking for cmdline mode on connector 78
[    3.570573] [drm:drm_target_preferred] looking for preferred mode on connector 78 0
[    3.570578] [drm:drm_target_preferred] found mode 800x600

[mcerveny]

Ping.
Do you have patch for that ?
Is anyone working on it ?

[markyzq]

1. nearly all output modes are blocked for DMT/VESA modes
   seems rk3288 need a similar modify to commit d072a98, get accurate clock for hdmi.
   commit d072a98 is for rk3368

2. check modes to "fail-safe" framebuffer size (1024x768) and not to maximum available
   the problem is drm framework limit, when there is no connector plug, drm framework hard code to use 1024x768 framebuffer size.
   drivers/gpu/drm/drm_fb_helper.c
   sizes.fb_width = sizes.surface_width = 1024;
   sizes.fb_height = sizes.surface_height = 768;
   You can custom modify it for you product, or if we can solved issue 1), this problem would disappear.

[mcerveny]

I tried this:

diff --git a/drivers/clk/rockchip/clk-rk3288.c b/drivers/clk/rockchip/clk-rk3288.c
index 7ceee5c..47352ef 100644
--- a/drivers/clk/rockchip/clk-rk3288.c
+++ b/drivers/clk/rockchip/clk-rk3288.c
@@ -179,6 +179,7 @@ PNAME(mux_aclk_cpu_src_p)   = { "cpll_aclk_cpu", "gpll_aclk_cpu" };
 PNAME(mux_pll_src_cpll_gpll_p)         = { "cpll", "gpll" };
 PNAME(mux_pll_src_npll_cpll_gpll_p)    = { "npll", "cpll", "gpll" };
 PNAME(mux_pll_src_cpll_gpll_npll_p)    = { "cpll", "gpll", "npll" };
+PNAME(mux_pll_src_dmycpll_dmygpll_npll_p)      = { "dummy_cpll", "dummy_gpll", "npll" };
 PNAME(mux_pll_src_cpll_gpll_usb480m_p) = { "cpll", "gpll", "usbphy480m_src" };
 PNAME(mux_pll_src_cpll_gll_usb_npll_p) = { "cpll", "gpll", "usbphy480m_src", "npll" };
 
@@ -428,7 +429,7 @@ static struct rockchip_clk_branch rk3288_clk_branches[] __initdata = {
                        RK3288_CLKSEL_CON(30), 14, 2, MFLAGS, 8, 5, DFLAGS,
                        RK3288_CLKGATE_CON(3), 4, GFLAGS),
 
-       COMPOSITE(DCLK_VOP0, "dclk_vop0", mux_pll_src_cpll_gpll_npll_p, 0,
+       COMPOSITE(DCLK_VOP0, "dclk_vop0", mux_pll_src_dmycpll_dmygpll_npll_p, CLK_SET_RATE_PARENT,
                        RK3288_CLKSEL_CON(27), 0, 2, MFLAGS, 8, 8, DFLAGS,
                        RK3288_CLKGATE_CON(3), 1, GFLAGS),
        COMPOSITE(DCLK_VOP1, "dclk_vop1", mux_pll_src_cpll_gpll_npll_p, 0,

But kernel crash:

[    3.377843] Unable to handle kernel NULL pointer dereference at virtual address 00000000
...
[    3.377912] PC is at clk_hw_round_rate+0x28/0x54
...
[    3.379627] [<c08bb8cc>] (clk_hw_round_rate) from [<c08c0c5c>] (divider_round_rate+0x280/0x3b0)
[    3.379640] [<c08c0c5c>] (divider_round_rate) from [<c08c0e20>] (clk_divider_round_rate+0x94/0x9c)
[    3.379653] [<c08c0e20>] (clk_divider_round_rate) from [<c08c1d4c>] (clk_composite_determine_rate+0x128/0x1ec)
[    3.379667] [<c08c1d4c>] (clk_composite_determine_rate) from [<c08bb818>] (clk_core_round_rate_nolock+0x58/0xb4)
[    3.379680] [<c08bb818>] (clk_core_round_rate_nolock) from [<c08bdc74>] (clk_round_rate+0x48/0x68)
[    3.379697] [<c08bdc74>] (clk_round_rate) from [<c04d34d0>] (vop_crtc_mode_valid+0x50/0x80)
[    3.379716] [<c04d34d0>] (vop_crtc_mode_valid) from [<c04c983c>] (dw_hdmi_rockchip_mode_valid+0x138/0x15c)
[    3.379732] [<c04c983c>] (dw_hdmi_rockchip_mode_valid) from [<c04e26c8>] (dw_hdmi_connector_mode_valid+0x28/0x34)
[    3.379750] [<c04e26c8>] (dw_hdmi_connector_mode_valid) from [<c04998d4>] (drm_helper_probe_single_connector_modes_merge_bits+0x36c/0x448)
[    3.379767] [<c04998d4>] (drm_helper_probe_single_connector_modes_merge_bits) from [<c04999cc>] (drm_helper_probe_single_connector_modes+0x1c/0x20)
[    3.379781] [<c04999cc>] (drm_helper_probe_single_connector_modes) from [<c04a2164>] (drm_fb_helper_probe_connector_modes+0x58/0x68)
[    3.379794] [<c04a2164>] (drm_fb_helper_probe_connector_modes) from [<c04a4540>] (drm_fb_helper_hotplug_event+0x9c/0xe8)
[    3.379807] [<c04a4540>] (drm_fb_helper_hotplug_event) from [<c04d0684>] (rockchip_drm_output_poll_changed+0x28/0x2c)
[    3.379821] [<c04d0684>] (rockchip_drm_output_poll_changed) from [<c0499288>] (drm_kms_helper_hotplug_event+0x34/0x38)
[    3.379835] [<c0499288>] (drm_kms_helper_hotplug_event) from [<c0499bc4>] (drm_helper_hpd_irq_event+0x128/0x15c)
[    3.379847] [<c0499bc4>] (drm_helper_hpd_irq_event) from [<c04e2d40>] (repo_hpd_event+0x24/0x28)
[    3.379859] [<c04e2d40>] (repo_hpd_event) from [<c01347b4>] (process_one_work+0x234/0x418)
[    3.379872] [<c01347b4>] (process_one_work) from [<c0135558>] (worker_thread+0x2cc/0x40c)
[    3.379884] [<c0135558>] (worker_thread) from [<c013a0e8>] (kthread+0x100/0x118)
[    3.379898] [<c013a0e8>] (kthread) from [<c0107378>] (ret_from_fork+0x14/0x3c)

[mcerveny]

I temporary resolve this issue by workaround - https://tinkerboarding.co.uk/forum/thread-321-post-1350.html#pid1350

[markyzq]

apply attach patch, and assigned dclk on dtsi, then may solved your problem

assigned-clocks = <&cru DCLK_VOP0>;
assigned-clock-parents = <&cru PLL_NPLL>;

[markyzq]

rk3288_npll_for_vop0.patch.txt

[mcerveny]

Thanks, but partially working.
Some resolution (NPLL/DCLK_VOP0 clock) does not work at all (blank output) or blinking (few seconds show and then resync - probably PLL lost sync ?).
Working NPLL clocks:
65000 kHz
78750 kHz
135000 kHz
NOT working NPLL clocks:
1080000 kHz (this works in my workaround perfectly eg. NPLL 216000000 and divide by 2 to get DCLK_VOP0)
75000 kHz
I suppose that PLL should use some frequency that is multiply of requested DCLK_VOP0.
I cannot view problem on TMDS clock pins with my oscilloscope to verify problem - try to test clock in your HW lab.

Test:

# egrep  'npll|dclk_vop0' /sys/kernel/debug/clk/clk_summary
    pll_npll                              1            1   108000000          0 0  
       npll                               1            1   108000000          0 0  
          dclk_vop0                       2            3   108000000          0 0  

[mcerveny]

Kwiboo/linux-rockchip@580da0d fixes rk3328 platform for me (not using rk3288 any more).