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Message-ID: <1982691.ZDuzTFTUUe@diego>
Date: Tue, 08 Dec 2015 16:33:39 +0100
From: Heiko Stübner <heiko@...ech.de>
To: Yakir Yang <ykk@...k-chips.com>,
Thierry Reding <treding@...dia.com>
Cc: Inki Dae <inki.dae@...sung.com>,
Mark Yao <mark.yao@...k-chips.com>,
Jingoo Han <jingoohan1@...il.com>,
Krzysztof Kozlowski <k.kozlowski@...sung.com>,
Rob Herring <robh+dt@...nel.org>,
Andrzej Hajda <a.hajda@...sung.com>,
Joonyoung Shim <jy0922.shim@...sung.com>,
Seung-Woo Kim <sw0312.kim@...sung.com>,
Kyungmin Park <kyungmin.park@...sung.com>,
Russell King <linux@....linux.org.uk>,
emil.l.velikov@...il.com,
Gustavo Padovan <gustavo.padovan@...labora.co.uk>,
Kishon Vijay Abraham I <kishon@...com>, ajaynumb@...il.com,
javier@....samsung.com, Andy Yan <andy.yan@...k-chips.com>,
dri-devel@...ts.freedesktop.org, devicetree@...r.kernel.org,
linux-kernel@...r.kernel.org, linux-samsung-soc@...r.kernel.org,
linux-rockchip@...ts.infradead.org,
linux-arm-kernel@...ts.infradead.org
Subject: Re: [PATCH v10 0/17] Add Analogix Core Display Port Driver
Hi Yakir,
Am Montag, 7. Dezember 2015, 14:37:19 schrieb Yakir Yang:
> The Samsung Exynos eDP controller and Rockchip RK3288 eDP controller
> share the same IP, so a lot of parts can be re-used. I split the common
> code into bridge directory, then rk3288 and exynos only need to keep
> some platform code. Cause I can't find the exact IP name of exynos dp
> controller, so I decide to name dp core driver with "analogix" which I
> find in rk3288 eDP TRM
[...]
> Changes in v10:
> - Correct the ROCKCHIP_ANALOGIX_DP indentation in Kconfig to tabs here
> (Heiko) - Fix the wrong macro value of
> GRF_EDP_REF_CLK_SEL_INTER_HIWORD_MASK BIT(4) -> BIT(20)
> - Remove the surplus "plat_data" check. (Heiko)
> - switch (dp->plat_data && dp->plat_data->dev_type) {
> + switch (dp->plat_data->dev_type) {
> - Revert parts of Gustavo Padovan's changes in commit:
> drm/exynos: do not start enabling DP at bind() phase
> Add dp phy poweron function in bind time.
The hotplug issue is still present, but I think I found the cause. When
the first detect call happens, the display simply is still off. I just did
some very basic tracing [0] and it seems the display simply is not enabled
when it is supposed to get detected.
And it seems injecting a drm_panel_prepare early for _testing_ [1] really
did make the hotplug work on both my jerry and minnie.
So I guess we should somehow make sure the panel is actually powered when
detection is running. Although I'm not sure yet, how that should look like.
Intuition suggests, making drm_panel calls nestable (similar to
clk_prepare/unprepare, etc) and simply wrapping the detection code
in a prepare-unprepare calls, but I'm not sure if Thierry might have other
ideas ;-)
Also my "log" below suggests some sort of mismatch between
prepare/unprepare calls, as there are a lot more of the prepare-side.
And the locking issue also seems to be still there [2].
Heiko
[0]
[ 2.797383] analogix_dp_reset
[ 2.800709] analogix_dp_init_hpd
[ 2.803960] analogix_dp_init_video
[ 2.807653] rockchip-drm display-subsystem: bound ff970000.dp (ops rockchip_dp_component_ops)
[ 2.817176] [drm] Supports vblank timestamp caching Rev 2 (21.10.2013).
[ 2.823799] [drm] No driver support for vblank timestamp query.
[ 2.829947] analogix_dp_detect
[ 2.833015] analogix_dp_get_plug_in_status: hpd status 0
...
[ 2.893425] analogix_dp_get_plug_in_status: hpd status 0
[ 2.893456] rockchip-dp ff970000.dp: failed to get hpd plug status, try to force hpd
[ 2.893458] analogix_dp_force_hpd
[ 2.893464] analogix_dp_get_plug_in_status: hpd status 112
[ 2.893470] panel_simple_prepare
[ 2.952183] rockchip-dp ff970000.dp: EDID data does not include any extensions.
[ 2.961727] panel_simple_get_modes
[ 3.432154] analogix_dp_detect
[ 3.432158] analogix_dp_get_plug_in_status: hpd status 120
[ 3.432160] panel_simple_prepare
[ 3.433731] rockchip-dp ff970000.dp: EDID data does not include any extensions.
[ 3.443268] panel_simple_get_modes
[ 3.444668] panel_simple_prepare
[ 3.444755] analogix_dp_reset
[ 3.445078] analogix_dp_init_hpd
[ 3.445096] panel_simple_disable
[ 3.455349] analogix_dp_init_video
[ 3.558323] rockchip-dp ff970000.dp: Timeout of video streamclk ok
[ 3.558326] rockchip-dp ff970000.dp: unable to config video
[ 3.558328] panel_simple_enable
[ 3.573915] analogix_dp_detect
[ 3.573919] analogix_dp_get_plug_in_status: hpd status 72
[ 3.573921] panel_simple_prepare
[1]
diff --git a/drivers/gpu/drm/rockchip/analogix_dp-rockchip.c b/drivers/gpu/drm/rockchip/analogix_dp-rockchip.c
index 3990951..0c2dca5 100644
--- a/drivers/gpu/drm/rockchip/analogix_dp-rockchip.c
+++ b/drivers/gpu/drm/rockchip/analogix_dp-rockchip.c
@@ -399,6 +399,8 @@ static int rockchip_dp_probe(struct platform_device *pdev)
dp->plat_data.panel = panel;
+drm_panel_prepare(dp->plat_data.panel);
+
/*
* We just use the drvdata until driver run into component
* add function, and then we would set drvdata to null, so
[2]
[ 11.971277] panel_simple_get_modes
[ OK ] Started LSB: X display manager for KDE.
[ OK ] Started LSB: Speech Dispatcher.
[ 12.007120] panel_simple_disable
[ 12.012323]
[ 12.013820] ======================================================
[ 12.019993] [ INFO: possible circular locking dependency detected ]
[ 12.026250] 4.4.0-rc3+ #2755 Not tainted
[ 12.030165] -------------------------------------------------------
[ 12.036417] Xorg/793 is trying to acquire lock:
[ 12.040855] ((&dp->hotplug_work)){+.+...}[ 12.040870]
[ 12.040870] but task is already holding lock:
[ 12.040871] (crtc_ww_class_mutex){+.+.+.}, at: [<c0383600>] drm_modeset_lock+0x84/0x104
[ 12.040881]
[ 12.040881] which lock already depends on the new lock.
[ 12.040881]
[ 12.040882]
[ 12.040882] the existing dependency chain (in reverse order) is:
[ 12.040883]
[ 12.040883] -> #2 (crtc_ww_class_mutex){+.+.+.}:
[ 12.040887] [<c0756374>] mutex_lock_nested+0x78/0x41c
[ 12.040893] [<c038365c>] drm_modeset_lock+0xe0/0x104
[ 12.040896] [<c0377888>] drm_mode_getconnector+0x168/0x38c
[ 12.040902] [<c036ae58>] drm_ioctl+0x274/0x408
[ 12.040907] [<c017cbc8>] do_vfs_ioctl+0x670/0x750
[ 12.040911] [<c017cd04>] SyS_ioctl+0x5c/0x84
[ 12.040914] [<c000ff80>] ret_fast_syscall+0x0/0x1c
[ 12.040920]
[ 12.040920] -> #1 (&dev->mode_config.mutex){+.+.+.}:
[ 12.040924] [<c0756374>] mutex_lock_nested+0x78/0x41c
[ 12.040928] [<c035b3b4>] drm_helper_hpd_irq_event+0x40/0x150
[ 12.040934] [<c038e0b0>] analogix_dp_hotplug+0x24/0x28
[ 12.040938] [<c00450c4>] process_one_work+0x328/0x668
[ 12.040942] [<c0046334>] worker_thread+0x2cc/0x41c
[ 12.040945] [<c004bbe8>] kthread+0xf4/0x10c
[ 12.040950] [<c0010010>] ret_from_fork+0x14/0x24
[ 12.040954]
[ 12.040954] -> #0 ((&dp->hotplug_work)){+.+...}:
[ 12.040958] [<c007f4ac>] lock_acquire+0x178/0x218
[ 12.040963] [<c00437d0>] flush_work+0x4c/0x22c
[ 12.040966] [<c038e45c>] analogix_dp_bridge_disable+0x74/0xf0
[ 12.040970] [<c0385ef4>] drm_bridge_disable+0x34/0x38
[ 12.040973] [<c0359044>] drm_crtc_helper_set_mode+0x200/0x424
[ 12.040977] [<c0359a38>] drm_crtc_helper_set_config+0x6c0/0x988
[ 12.040981] [<c0373ba8>] drm_mode_set_config_internal+0x60/0xdc
[ 12.040984] [<c0378938>] drm_mode_setcrtc+0x3cc/0x474
[ 12.040988] [<c036ae58>] drm_ioctl+0x274/0x408
[ 12.040991] [<c017cbc8>] do_vfs_ioctl+0x670/0x750
[ 12.040994] [<c017cd04>] SyS_ioctl+0x5c/0x84
[ 12.040997] [<c000ff80>] ret_fast_syscall+0x0/0x1c
[ 12.041001]
[ 12.041001] other info that might help us debug this:
[ 12.041001]
[ 12.041002] Chain exists of:
[ 12.041002] (&dp->hotplug_work) --> &dev->mode_config.mutex --> crtc_ww_class_mutex
[ 12.041007]
[ 12.041008] Possible unsafe locking scenario:
[ 12.041008]
[ 12.041009] CPU0 CPU1
[ 12.041010] ---- ----
[ 12.041011] lock(crtc_ww_class_mutex);
[ 12.041013] lock(&dev->mode_config.mutex);
[ 12.041016] lock(crtc_ww_class_mutex);
[ 12.041018] lock((&dp->hotplug_work));
[ 12.041020]
[ 12.041020] *** DEADLOCK ***
[ 12.041020]
[ 12.041023] 3 locks held by Xorg/793:
[ 12.041023] #0: (&dev->mode_config.mutex){+.+.+.}, at: [<c0383d48>] drm_modeset_lock_all+0x50/0xd8
[ 12.041030] #1: (crtc_ww_class_acquire){+.+.+.}, at: [<c0383d58>] drm_modeset_lock_all+0x60/0xd8
[ 12.041037] #2: (crtc_ww_class_mutex){+.+.+.}, at: [<c0383600>] drm_modeset_lock+0x84/0x104
[ 12.041044]
[ 12.041044] stack backtrace:
[ 12.041048] CPU: 3 PID: 793 Comm: Xorg Not tainted 4.4.0-rc3+ #2755
[ 12.041049] Hardware name: Rockchip (Device Tree)
[ 12.041059] [<c0019914>] (unwind_backtrace) from [<c0014bcc>] (show_stack+0x20/0x24)
[ 12.041066] [<c0014bcc>] (show_stack) from [<c02c4484>] (dump_stack+0x84/0xb8)
[ 12.041072] [<c02c4484>] (dump_stack) from [<c007a2b8>] (print_circular_bug+0x278/0x2cc)
[ 12.041078] [<c007a2b8>] (print_circular_bug) from [<c007e850>] (__lock_acquire+0x14a0/0x1aec)
[ 12.041082] [<c007e850>] (__lock_acquire) from [<c007f4ac>] (lock_acquire+0x178/0x218)
[ 12.041086] [<c007f4ac>] (lock_acquire) from [<c00437d0>] (flush_work+0x4c/0x22c)
[ 12.041091] [<c00437d0>] (flush_work) from [<c038e45c>] (analogix_dp_bridge_disable+0x74/0xf0)
[ 12.041097] [<c038e45c>] (analogix_dp_bridge_disable) from [<c0385ef4>] (drm_bridge_disable+0x34/0x38)
[ 12.041102] [<c0385ef4>] (drm_bridge_disable) from [<c0359044>] (drm_crtc_helper_set_mode+0x200/0x424)
[ 12.041108] [<c0359044>] (drm_crtc_helper_set_mode) from [<c0359a38>] (drm_crtc_helper_set_config+0x6c0/0x988)
[ 12.041114] [<c0359a38>] (drm_crtc_helper_set_config) from [<c0373ba8>] (drm_mode_set_config_internal+0x60/0xdc)
[ 12.041119] [<c0373ba8>] (drm_mode_set_config_internal) from [<c0378938>] (drm_mode_setcrtc+0x3cc/0x474)
[ 12.041124] [<c0378938>] (drm_mode_setcrtc) from [<c036ae58>] (drm_ioctl+0x274/0x408)
[ 12.041129] [<c036ae58>] (drm_ioctl) from [<c017cbc8>] (do_vfs_ioctl+0x670/0x750)
[ 12.041134] [<c017cbc8>] (do_vfs_ioctl) from [<c017cd04>] (SyS_ioctl+0x5c/0x84)
[ 12.041138] [<c017cd04>] (SyS_ioctl) from [<c000ff80>] (ret_fast_syscall+0x0/0x1c)
[ 12.041210] panel_simple_unprepare
[ 12.041359] panel_simple_prepare
[ 12.101638] analogix_dp_reset
[ 12.101879] analogix_dp_init_hpd
[ 12.101897] panel_simple_disable
[ 12.108543] analogix_dp_irq_handler: irq-type 0
[ 12.110452] rockchip-dp ff970000.dp: Link Training Clock Recovery success
[ 12.111900] rockchip-dp ff970000.dp: Link Training success!
[ 12.113384] analogix_dp_init_video
[ 12.215825] rockchip-dp ff970000.dp: Timeout of video streamclk ok
[ 12.215829] rockchip-dp ff970000.dp: unable to config video
[ 12.215832] panel_simple_enable
,at: [<c0043784>] flush_work+0x0/0x22c
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