Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751564AbbLIOwA (ORCPT ); Wed, 9 Dec 2015 09:52:00 -0500 Received: from gloria.sntech.de ([95.129.55.99]:34481 "EHLO gloria.sntech.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751106AbbLIOv6 convert rfc822-to-8bit (ORCPT ); Wed, 9 Dec 2015 09:51:58 -0500 From: Heiko =?ISO-8859-1?Q?St=FCbner?= To: Yakir Yang Cc: Thierry Reding , Inki Dae , Mark Yao , Jingoo Han , Krzysztof Kozlowski , Rob Herring , Andrzej Hajda , Joonyoung Shim , Seung-Woo Kim , Kyungmin Park , Russell King , emil.l.velikov@gmail.com, Gustavo Padovan , Kishon Vijay Abraham I , ajaynumb@gmail.com, javier@osg.samsung.com, Andy Yan , dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-samsung-soc@vger.kernel.org, linux-rockchip@lists.infradead.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v10 0/17] Add Analogix Core Display Port Driver Date: Wed, 09 Dec 2015 15:51:33 +0100 Message-ID: <1572876.arr7htU3E0@diego> User-Agent: KMail/4.14.10 (Linux/4.2.0-1-amd64; KDE/4.14.13; x86_64; ; ) In-Reply-To: <5667A4B6.4090708@rock-chips.com> References: <1449470239-30667-1-git-send-email-ykk@rock-chips.com> <1982691.ZDuzTFTUUe@diego> <5667A4B6.4090708@rock-chips.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8BIT Content-Type: text/plain; charset="iso-8859-1" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 13131 Lines: 286 Hi Yakir, Am Mittwoch, 9. Dezember 2015, 11:49:10 schrieb Yakir Yang: > Thanks a lot for great debugging. > > On 12/08/2015 11:33 PM, Heiko St?bner wrote: > > 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. > > Aha, thanks, make a lot of sense. > > > 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. > > Agree, panel should be powered up before DP controller start to detect > hotplug signal. > > > 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 ;-) > > Due to the panel power status would influence the hotplug status, so I > think we don't > need to unprepared the panel unless in driver enter into suspend time. > Things I want: > > 1. Prepared the panel in driver *bind time* > 2. Enable the panel in driver *bridge->enable time* > 3. Disable the panel in driver *bridge->disable time* > 4. Unprepared the panel in driver*suspend time * > 5. Re-prepared the panel in driver *resume time* 6. Unprepare the panel in driver at *unbind time* otherwise going that way looks nice. > > Also my "log" below suggests some sort of mismatch between > > prepare/unprepare calls, as there are a lot more of the prepare-side. > > Yes, it's a typo too. I shouldn't place the panel->prepare in > connector->get_modes, > cause userspace would try to call get_modes once it receive the hotplug > event, so > there wouldn't have a match between panel prepare/unprepare. > > Previously, I just want to ensure that panel should be power-up when > driver try to > read the EDID from panel, so for now must remove the prepare from > get_modes time :) > > > And the locking issue also seems to be still there [2]. > > Hmm, I haven't meet this dead lock on my chromebook (ChromeOS + 4.4-rc3 > Kernel) > > After look at the dead lock trace, I guess this dead lock would happened > when hotplug > event happened in bridge->disable time, not sure. Would try to find > more in trace log > and try to reproduce this. It is not an actual deadlock, but a warning that a deadlock might happen. So you need to have LOCKDEP on. My kernels are currently running with CONFIG_DEBUG_LOCK_ALLOC=y CONFIG_PROVE_LOCKING=y CONFIG_LOCKDEP=y CONFIG_DEBUG_LOCKDEP=y CONFIG_DEBUG_ATOMIC_SLEEP=y and I see this mostly when changing between X11, console and back to X11. Heiko > > 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: [] > > 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] [] mutex_lock_nested+0x78/0x41c > > [ 12.040893] [] drm_modeset_lock+0xe0/0x104 > > [ 12.040896] [] drm_mode_getconnector+0x168/0x38c > > [ 12.040902] [] drm_ioctl+0x274/0x408 > > [ 12.040907] [] do_vfs_ioctl+0x670/0x750 > > [ 12.040911] [] SyS_ioctl+0x5c/0x84 > > [ 12.040914] [] ret_fast_syscall+0x0/0x1c > > [ 12.040920] > > [ 12.040920] -> #1 (&dev->mode_config.mutex){+.+.+.}: > > [ 12.040924] [] mutex_lock_nested+0x78/0x41c > > [ 12.040928] [] drm_helper_hpd_irq_event+0x40/0x150 > > [ 12.040934] [] analogix_dp_hotplug+0x24/0x28 > > [ 12.040938] [] process_one_work+0x328/0x668 > > [ 12.040942] [] worker_thread+0x2cc/0x41c > > [ 12.040945] [] kthread+0xf4/0x10c > > [ 12.040950] [] ret_from_fork+0x14/0x24 > > [ 12.040954] > > [ 12.040954] -> #0 ((&dp->hotplug_work)){+.+...}: > > [ 12.040958] [] lock_acquire+0x178/0x218 > > [ 12.040963] [] flush_work+0x4c/0x22c > > [ 12.040966] [] analogix_dp_bridge_disable+0x74/0xf0 > > [ 12.040970] [] drm_bridge_disable+0x34/0x38 > > [ 12.040973] [] drm_crtc_helper_set_mode+0x200/0x424 > > [ 12.040977] [] drm_crtc_helper_set_config+0x6c0/0x988 > > [ 12.040981] [] drm_mode_set_config_internal+0x60/0xdc > > [ 12.040984] [] drm_mode_setcrtc+0x3cc/0x474 > > [ 12.040988] [] drm_ioctl+0x274/0x408 > > [ 12.040991] [] do_vfs_ioctl+0x670/0x750 > > [ 12.040994] [] SyS_ioctl+0x5c/0x84 > > [ 12.040997] [] 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: [] > > drm_modeset_lock_all+0x50/0xd8 [ 12.041030] #1: > > (crtc_ww_class_acquire){+.+.+.}, at: [] > > drm_modeset_lock_all+0x60/0xd8 [ 12.041037] #2: > > (crtc_ww_class_mutex){+.+.+.}, at: [] > > 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] [] (unwind_backtrace) from [] > > (show_stack+0x20/0x24) [ 12.041066] [] (show_stack) from > > [] (dump_stack+0x84/0xb8) [ 12.041072] [] > > (dump_stack) from [] (print_circular_bug+0x278/0x2cc) [ > > 12.041078] [] (print_circular_bug) from [] > > (__lock_acquire+0x14a0/0x1aec) [ 12.041082] [] > > (__lock_acquire) from [] (lock_acquire+0x178/0x218) [ > > 12.041086] [] (lock_acquire) from [] > > (flush_work+0x4c/0x22c) [ 12.041091] [] (flush_work) from > > [] (analogix_dp_bridge_disable+0x74/0xf0) [ 12.041097] > > [] (analogix_dp_bridge_disable) from [] > > (drm_bridge_disable+0x34/0x38) [ 12.041102] [] > > (drm_bridge_disable) from [] > > (drm_crtc_helper_set_mode+0x200/0x424) [ 12.041108] [] > > (drm_crtc_helper_set_mode) from [] > > (drm_crtc_helper_set_config+0x6c0/0x988) [ 12.041114] [] > > (drm_crtc_helper_set_config) from [] > > (drm_mode_set_config_internal+0x60/0xdc) [ 12.041119] [] > > (drm_mode_set_config_internal) from [] > > (drm_mode_setcrtc+0x3cc/0x474) [ 12.041124] [] > > (drm_mode_setcrtc) from [] (drm_ioctl+0x274/0x408) [ > > 12.041129] [] (drm_ioctl) from [] > > (do_vfs_ioctl+0x670/0x750) [ 12.041134] [] (do_vfs_ioctl) > > from [] (SyS_ioctl+0x5c/0x84) [ 12.041138] [] > > (SyS_ioctl) from [] (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: [] flush_work+0x0/0x22c -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/