From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yakir Yang Subject: Re: [PATCH v14.1 01/17] drm: bridge: analogix/dp: split exynos dp driver to bridge directory Date: Wed, 8 Jun 2016 09:28:32 +0800 Message-ID: <575774C0.4000900@rock-chips.com> References: <1455534485-1154-1-git-send-email-ykk@rock-chips.com> <1455534576-1486-1-git-send-email-ykk@rock-chips.com> <1811552.qvsCm7GUs1@diego> <417ed48e-74e1-f747-34b9-0d1031a3d862@osg.samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <417ed48e-74e1-f747-34b9-0d1031a3d862@osg.samsung.com> Sender: linux-samsung-soc-owner@vger.kernel.org To: Javier Martinez Canillas Cc: =?UTF-8?Q?Heiko_St=c3=bcbner?= , Inki Dae , Andrzej Hajda , Joonyoung Shim , Seung-Woo Kim , Kyungmin Park , Jingoo Han , Thierry Reding , Krzysztof Kozlowski , Rob Herring , Mark Yao , Russell King , djkurtz@chromium.org, Sean Paul , Kukjin Kim , Kumar Gala , emil.l.velikov@gmail.com, Ian Campbell , Gustavo Padovan , Kishon Vijay Abraham I , Pawel Moll , ajaynumb@gmail.com, robherring2@gmail.com, Andy Yan , dri-d List-Id: devicetree@vger.kernel.org Hi Javier, On 06/08/2016 01:06 AM, Javier Martinez Canillas wrote: > Hello Yakir, > > On 03/17/2016 05:47 PM, Heiko St=FCbner wrote: >> Split the dp core driver from exynos directory to bridge directory, >> and rename the core driver to analogix_dp_*, rename the platform >> code to exynos_dp. >> >> Beside the new analogix_dp driver would export six hooks. >> "analogix_dp_bind()" and "analogix_dp_unbind()" >> "analogix_dp_suspned()" and "analogix_dp_resume()" >> "analogix_dp_detect()" and "analogix_dp_get_modes()" >> >> The bind/unbind symbols is used for analogix platform driver to conn= ect >> with analogix_dp core driver. And the detect/get_modes is used for a= nalogix >> platform driver to init the connector. >> >> They reason why connector need register in helper driver is rockchip= drm >> haven't implement the atomic API, but Exynos drm have implement it, = so >> there would need two different connector helper functions, that's wh= y we >> leave the connector register in helper driver. >> >> Signed-off-by: Yakir Yang >> --- > Marc reported that his Exynos5250 Snow Chromebook fails to boot with = v4.7-rc. > > I've done a git bisect and tracked down to this commit. The problem i= s a NULL > pointer dereference to connector->dev in drm_mode_create(connector->d= ev) when > called from exynos_dp_get_modes(). The error log is at [1]. > > I'm trying to figure out the issue but wanted to mention in case you = have any > hints about what could be the cause. AFAICT the problem is related to= the fact > that drm_connector_init() is called in analogix_dp_bridge_attach() an= d the > connector passed as argument is the one in struct analogix_dp_device = *dp, but > later exynos_dp_get_modes() calls drm_mode_create() passing the conne= ctor in > struct exynos_dp_device *dp, which has not been previously initialize= d. Agree, this should be the problem, exynos_dp->connector haven't been initialized, driver should make exynos_dp->dp to a connector point, and record the passing connector in exynos_dp_bridge_attach(), that should fix this problem. Thanks, - Yakir diff --git a/drivers/gpu/drm/exynos/exynos_dp.c=20 b/drivers/gpu/drm/exynos/exynos_dp.c index 468498e..4c1fb3f 100644 --- a/drivers/gpu/drm/exynos/exynos_dp.c +++ b/drivers/gpu/drm/exynos/exynos_dp.c @@ -34,7 +34,7 @@ struct exynos_dp_device { struct drm_encoder encoder; - struct drm_connector connector; + struct drm_connector *connector; struct drm_bridge *ptn_bridge; struct drm_device *drm_dev; struct device *dev; @@ -70,7 +70,7 @@ static int exynos_dp_poweroff(struct=20 analogix_dp_plat_data *plat_data) static int exynos_dp_get_modes(struct analogix_dp_plat_data *plat_dat= a) { struct exynos_dp_device *dp =3D to_dp(plat_data); - struct drm_connector *connector =3D &dp->connector; + struct drm_connector *connector =3D dp->connector; struct drm_display_mode *mode; int num_modes =3D 0; @@ -103,6 +103,7 @@ static int exynos_dp_bridge_attach(struct=20 analogix_dp_plat_data *plat_data, int ret; drm_connector_register(connector); + dp->connector =3D connector; /* Pre-empt DP connector creation if there's a bridge */ if (dp->ptn_bridge) { > [1] > [ 4.175676] Unable to handle kernel NULL pointer dereference at vi= rtual address 00000210 > [ 4.182793] pgd =3D c0004000 > [ 4.185171] [00000210] *pgd=3D00000000 > [ 4.188657] Internal error: Oops: 5 [#1] PREEMPT SMP ARM > [ 4.194164] Modules linked in: > [ 4.196964] CPU: 1 PID: 68 Comm: kworker/1:1 Not tainted 4.7.0-rc2= -next-20160606-00006-g876c3150327a #97 > [ 4.206565] Hardware name: SAMSUNG EXYNOS (Flattened Device Tree) > [ 4.212582] Workqueue: events hdmi_hotplug_work_func > [ 4.217383] task: ed758000 ti: ed75c000 task.ti: ed75c000 > [ 4.222887] PC is at __mutex_lock_slowpath+0x6c/0x404 > [ 4.227913] LR is at preempt_count_add+0xa4/0x140 > [ 4.232592] pc : [] lr : [] psr: 6000009= 3 > [ 4.232592] sp : ed75dd80 ip : 00000000 fp : ee8c1180 > [ 4.244193] r10: 00000300 r9 : ed758000 r8 : 00000001 > [ 4.249262] r7 : 60000013 r6 : c0b473a8 r5 : 00000210 r4 : 0000= 020c > [ 4.261955] r3 : 00000000 r2 : 00000001 r1 : ee8c2808 r0 : 0000= 0000 > [ 4.273270] Flags: nZCv IRQs off FIQs on Mode SVC_32 ISA ARM = Segment none > [ 4.285336] Control: 10c5387d Table: 4000406a DAC: 00000051 > [ 4.295885] Process kworker/1:1 (pid: 68, stack limit =3D 0xed75c2= 10) > [ 4.306979] Stack: (0xed75dd80 to 0xed75e000) > [ 4.316102] dd80: ee8c1180 c03dd21c ee8f0820 00000001 0000020c 000= 0020c 00000000 00000000 > [ 4.329201] dda0: 00000001 dededede 00000300 c06d2578 ee8c2808 c03= d00f4 ee801d80 c0b0261c > [ 4.342362] ddc0: 00000041 ee8c2800 00000000 00000001 ee8f0810 ee8= f0b65 c074d2b4 c03d35b0 > [ 4.353140] dde0: 00000000 00000300 ee8c1180 c03d81d0 c387cf74 ee8= f0820 00000001 c03eaffc > [ 4.361811] de00: 00000000 ee8f0820 00000001 c03f28bc ee8f0b65 c06= d400c ee8c1180 006d40a4 > [ 4.370483] de20: 00000000 01820a11 81010300 00000100 00000064 ee8= f085c ee8f0820 c0b1f894 > [ 4.379150] de40: c3872800 c0b82fac c074d2b4 c03b7550 c0b13274 c03= 27974 00000001 eefb8530 > [ 4.387805] de60: 00000556 00000000 c38729b0 c3872800 ee8c1180 000= 00001 ee8c7000 00000000 > [ 4.396467] de80: 00000556 00000300 c38729b0 00000002 ee8c1180 c03= c107c ee8c7000 c3872800 > [ 4.405121] dea0: ee8c7240 c3872800 c0b82fac c03c3268 c3872ad4 000= 00001 c3872ae0 c03b7af0 > [ 4.413776] dec0: eefb8000 c0139804 00000000 c0136484 ee8a0000 ee8= c1180 c3870b4c eefb7b00 > [ 4.422415] dee0: eefbb000 00000000 00000000 eefb7b00 ee8c1180 c01= 2ff2c 00000008 eefb7b24 > [ 4.431045] df00: eefb7b00 ee8c1198 00000008 eefb7b24 c0b02100 ed7= 5c000 eefb7b00 c0130178 > [ 4.439664] df20: ed75c000 ee863040 ee8c1180 00000000 ee863040 ee8= c1180 c0130140 00000000 > [ 4.448274] df40: 00000000 00000000 00000000 c0135454 00000000 000= 00000 00000000 ee8c1180 > [ 4.456879] df60: 00000000 00000000 dead4ead ffffffff ffffffff ed7= 5df74 ed75df74 00000000 > [ 4.465462] df80: 00000000 dead4ead ffffffff ffffffff ed75df90 ed7= 5df90 ed75dfac ee863040 > [ 4.474028] dfa0: c0135378 00000000 00000000 c0107978 00000000 000= 00000 00000000 00000000 > [ 4.482597] dfc0: 00000000 00000000 00000000 00000000 00000000 000= 00000 00000000 00000000 > [ 4.491133] dfe0: 00000000 00000000 00000000 00000000 00000013 000= 00000 00000000 00000000 > [ 4.499643] [] (__mutex_lock_slowpath) from []= (mutex_lock+0xc/0x24) > [ 4.507102] IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready > [ 4.514264] [] (mutex_lock) from [] (drm_mode_= object_get_reg+0x28/0x80) > [ 4.522981] [] (drm_mode_object_get_reg) from [] (drm_mode_object_get+0x18/0x20) > [ 4.532491] [] (drm_mode_object_get) from [] (= drm_mode_create+0x3c/0x58) > [ 4.541316] [] (drm_mode_create) from [] (exyn= os_dp_get_modes+0x24/0x80) > [ 4.550160] [] (exynos_dp_get_modes) from [] (= analogix_dp_get_modes+0x198/0x278) > [ 4.559735] [] (analogix_dp_get_modes) from []= (drm_helper_probe_single_connector_modes+0x114/0x554) > [ 4.571078] [] (drm_helper_probe_single_connector_modes)= from [] (drm_fb_helper_probe_connector_modes+0x48/0x68) > [ 4.583513] [] (drm_fb_helper_probe_connector_modes) fro= m [] (drm_fb_helper_hotplug_event+0x70/0xdc) > [ 4.594921] [] (drm_fb_helper_hotplug_event) from [] (drm_helper_hpd_irq_event+0xd4/0x160) > [ 4.605474] [] (drm_helper_hpd_irq_event) from [] (process_one_work+0x124/0x338) > [ 4.615144] [] (process_one_work) from [] (wor= ker_thread+0x38/0x4d4) > [ 4.623764] [] (worker_thread) from [] (kthrea= d+0xdc/0xf4) > [ 4.631512] [] (kthread) from [] (ret_from_for= k+0x14/0x3c) > [ 4.639239] Code: e10f7000 f10c0080 e2845004 f595f000 (e1953f9f) > [ 4.645845] ---[ end trace 3bfc770b9638a54b ]--- > > Best regards,