Hi All once again, On 2018-03-01 12:06, Marek Szyprowski wrote: > > On 2018-03-01 09:50, Marek Szyprowski wrote: >> >> On 2018-01-30 21:28, Thierry Escande wrote: >>> This patchset includes cleanups, improvements, and bug fixes for >>> Rockchip DRM driver and PSR support. >>> >>> this patchset depends and needs to be applied on top of Rockchip rk3399 >>> eDP support [1]. >>> >>> [1] https://lkml.org/lkml/2018/1/10/682 >> >> I've applied this patchset on vanilla v4.16-rc1 and check how it >> works on >> Exynos5250-based Chromeboo Snow and Exynos5420-based Chromebook2 >> Peach-Pit >> boards. Sadly it breaks exynos_dp drm driver. >> >> Here is the log: >> >> [??? 3.540955] [drm] Exynos DRM: using 14400000.fimd device for DMA >> mapping operations >> [??? 3.548810] exynos-drm exynos-drm: bound 14400000.fimd (ops >> fimd_component_ops) >> [??? 3.555350] exynos-drm exynos-drm: bound 14450000.mixer (ops >> mixer_component_ops) >> [??? 3.564622] Unable to handle kernel NULL pointer dereference at >> virtual address 000007d8 >> [??? 3.571465] pgd = 28ffa2e4 >> [??? 3.573977] [000007d8] *pgd=00000000 >> [??? 3.577543] Internal error: Oops: 5 [#1] PREEMPT SMP ARM >> [??? 3.582817] Modules linked in: >> [??? 3.585846] CPU: 6 PID: 69 Comm: kworker/6:1 Not tainted >> 4.16.0-rc1-00062-ge25751974ba8 #3622 >> [??? 3.594369] Hardware name: SAMSUNG EXYNOS (Flattened Device Tree) >> [??? 3.600437] Workqueue: events deferred_probe_work_func >> [??? 3.605547] PC is at analogix_dp_resume+0x8/0xc0 >> [??? 3.610144] LR is at pm_generic_runtime_resume+0x2c/0x38 >> [??? 3.615434] pc : [<c0531b98>]??? lr : [<c0543fec>] psr: a0000113 >> [??? 3.621684] sp : ee13fbd8? ip : 0000001a? fp : 00000001 >> [??? 3.626885] r10: ee0eb080? r9 : c0552bd8? r8 : c0fb1d98 >> [??? 3.632090] r7 : eebb1010? r6 : eeae9808? r5 : 00000000? r4 : >> d4850415 >> [??? 3.638602] r3 : ee0ed010? r2 : b2d05e00? r1 : 00000000? r0 : >> 00000000 >> [??? 3.645109] Flags: NzCv? IRQs on? FIQs on? Mode SVC_32? ISA ARM >> Segment none >> [??? 3.652224] Control: 10c5387d? Table: 2000406a? DAC: 00000051 >> [??? 3.657944] Process kworker/6:1 (pid: 69, stack limit = 0x913205b4) >> [??? 3.664192] Stack: (0xee13fbd8 to 0xee140000) >> [??? 3.668523] fbc0: d4850415 00000000 >> [??? 3.676698] fbe0: eeae9808 c0543fec c0543fc0 c054ffb4 00000000 >> c0552d24 00000001 ee10b400 >> [??? 3.684852] fc00: c09d1500 eebb1010 eebb10b8 eebad810 00000000 >> 00000004 c0552bd8 00000000 >> [??? 3.693007] fc20: c016f5c4 c0547798 00000000 eebb1010 c0f05900 >> eebad810 c0552bd8 00000004 >> [??? 3.701163] fc40: 00000000 00000000 c016f5c4 c0547898 00000000 >> eebb1010 c0f05900 c0546ff4 >> [??? 3.709315] fc60: 60000113 c05475dc 00000001 eebb1010 00000000 >> c1711b78 eebb10b8 eebb1010 >> [??? 3.717470] fc80: 00000004 eebb10b8 60000113 eebb1010 00000000 >> c1711b78 c0f75ce0 c05475ec >> [??? 3.725624] fca0: 00000000 ecc59458 ecc5948c c0f75d4c 00000001 >> c053b95c ecc59458 00000001 >> [??? 3.733779] fcc0: 00000001 ecc59458 ecc59458 c0f75d4c c0f08448 >> c053ad08 ecc59458 ecc59460 >> [??? 3.741934] fce0: 00000000 c05390d0 ecc595a4 c1711c3c c0c7310c >> ecc61000 000001ff d186fc33 >> [??? 3.750088] fd00: ecc59458 ecc59398 c1715440 ecc59458 ecc61000 >> 000001ff 00000001 c0fb1738 >> [??? 3.758242] fd20: 00000000 c06764c4 c0fb1738 c0678130 ecc59010 >> eebb1010 00000000 ecc61000 >> [??? 3.766397] fd40: 000001ff c05321c8 00000003 c0c70b70 ecc59010 >> eebb1010 ee0ed010 eebb1010 >> [??? 3.774551] fd60: 00000000 00000000 ecc50b7c c0528e90 00000000 >> c053fa60 ed99b080 00000002 >> [??? 3.782706] fd80: 00000028 ee0ec340 ecc61000 c0535bc4 00000000 >> 00000000 ffffffff 00000000 >> [??? 3.790860] fda0: c0f62f80 ee0eb280 ecc61000 c0f63c80 ee031410 >> eebb0c10 c0fb1738 c0522ee8 >> [??? 3.799015] fdc0: c0522d8c ee0e82c0 00000050 00000004 ed99b050 >> ed99b080 c0f6375c c0536378 >> [??? 3.807169] fde0: 00000001 c0f63710 c0522b70 ee0ec340 ee0ec340 >> ed99b080 00000000 c0f63754 >> [??? 3.815324] fe00: ee0ec340 c1711bc0 c0f6333c 00000000 00000007 >> c05364fc ecc50b7c eebb1000 >> [??? 3.823479] fe20: ee0ed010 eebb1010 c0f6333c c0528fe4 ee13fe3c >> 00000000 00000000 ecc50b7c >> [??? 3.831633] fe40: 00000000 eebb1010 fffffdfb c053debc c053de6c >> eebb1010 c1711bbc 00000000 >> [??? 3.839787] fe60: c0fb19f0 c053bd18 00000001 c053e4d4 c0f6333c >> 00000000 ee13feb0 c053c054 >> [??? 3.847942] fe80: 00000001 c0f63bb4 c0fb19f0 c0fc50a0 c1711bbc >> c0539e4c ee8a3ad4 ed996a54 >> [??? 3.856096] fea0: eebb1010 eebb1044 c0f63c80 c053b970 eebb1010 >> 00000001 00000001 ee0d4100 >> [??? 3.864251] fec0: eebb1010 c0f63c80 c0f63b68 c053ad08 ee0d4100 >> eefa50c0 eebb1010 c053b258 >> [??? 3.872405] fee0: c053b21c ee0d4100 eefa50c0 ee13ff28 eefa8300 >> c0f63bd8 00000000 c0fa8ae5 >> [??? 3.880560] ff00: c0f0846c c014352c 00000001 00000000 c014347c >> 60000193 c09cb114 eefa50c0 >> [??? 3.888714] ff20: c0143c38 00000000 c0f63bd8 c110ef34 00000000 >> c0c71fdc c0f05900 ee0d4100 >> [??? 3.896869] ff40: eefa50c0 eefa50f4 c0143bfc c0fa9a27 00000008 >> ee0d4118 c0f05900 c0143b84 >> [??? 3.905024] ff60: c09d14d4 eeae7280 ee0d5000 eeae7280 ee0d5000 >> 00000000 eeae72b8 ee0d4100 >> [??? 3.913178] ff80: ee9b5eb0 c0143b50 00000000 c014a30c ee0d5000 >> c014a1e4 00000000 00000000 >> [??? 3.921332] ffa0: 00000000 00000000 00000000 c01010b4 00000000 >> 00000000 00000000 00000000 >> [??? 3.929486] ffc0: 00000000 00000000 00000000 00000000 00000000 >> 00000000 00000000 00000000 >> [??? 3.937641] ffe0: 00000000 00000000 00000000 00000000 00000013 >> 00000000 00000000 00000000 >> [??? 3.945800] [<c0531b98>] (analogix_dp_resume) from [<c0543fec>] >> (pm_generic_runtime_resume+0x2c/0x38) >> [??? 3.955001] [<c0543fec>] (pm_generic_runtime_resume) from >> [<c054ffb4>] (__genpd_runtime_resume+0x2c/0x8c) >> [??? 3.964543] [<c054ffb4>] (__genpd_runtime_resume) from >> [<c0552d24>] (genpd_runtime_resume+0x14c/0x258) >> [??? 3.973824] [<c0552d24>] (genpd_runtime_resume) from [<c0547798>] >> (__rpm_callback+0x134/0x214) >> [??? 3.982409] [<c0547798>] (__rpm_callback) from [<c0547898>] >> (rpm_callback+0x20/0x80) >> [??? 3.990126] [<c0547898>] (rpm_callback) from [<c0546ff4>] >> (rpm_resume+0x3a0/0x734) >> [??? 3.997672] [<c0546ff4>] (rpm_resume) from [<c05475ec>] >> (__pm_runtime_resume+0x64/0x9c) >> [??? 4.005654] [<c05475ec>] (__pm_runtime_resume) from [<c053b95c>] >> (__device_attach+0x8c/0x134) >> [??? 4.014157] [<c053b95c>] (__device_attach) from [<c053ad08>] >> (bus_probe_device+0x88/0x90) >> [??? 4.022314] [<c053ad08>] (bus_probe_device) from [<c05390d0>] >> (device_add+0x3a8/0x580) >> [??? 4.030209] [<c05390d0>] (device_add) from [<c06764c4>] >> (i2c_register_adapter+0xd4/0x3ec) >> [??? 4.038360] [<c06764c4>] (i2c_register_adapter) from [<c05321c8>] >> (analogix_dp_bind+0x2a0/0x410) >> [??? 4.047128] [<c05321c8>] (analogix_dp_bind) from [<c0528e90>] >> (exynos_dp_bind+0x9c/0x12c) >> [??? 4.055277] [<c0528e90>] (exynos_dp_bind) from [<c0535bc4>] >> (component_bind_all+0xfc/0x258) >> [??? 4.063605] [<c0535bc4>] (component_bind_all) from [<c0522ee8>] >> (exynos_drm_bind+0x15c/0x28c) >> [??? 4.072107] [<c0522ee8>] (exynos_drm_bind) from [<c0536378>] >> (try_to_bring_up_master+0x1b8/0x29c) >> [??? 4.080957] [<c0536378>] (try_to_bring_up_master) from >> [<c05364fc>] (component_add+0xa0/0x170) >> [??? 4.089545] [<c05364fc>] (component_add) from [<c0528fe4>] >> (exynos_dp_probe+0x64/0xb8) >> [??? 4.097437] [<c0528fe4>] (exynos_dp_probe) from [<c053debc>] >> (platform_drv_probe+0x50/0xb0) >> [??? 4.105766] [<c053debc>] (platform_drv_probe) from [<c053bd18>] >> (driver_probe_device+0x2b8/0x4a0) >> [??? 4.114615] [<c053bd18>] (driver_probe_device) from [<c0539e4c>] >> (bus_for_each_drv+0x44/0x8c) >> [??? 4.123115] [<c0539e4c>] (bus_for_each_drv) from [<c053b970>] >> (__device_attach+0xa0/0x134) >> [??? 4.131355] [<c053b970>] (__device_attach) from [<c053ad08>] >> (bus_probe_device+0x88/0x90) >> [??? 4.139509] [<c053ad08>] (bus_probe_device) from [<c053b258>] >> (deferred_probe_work_func+0x3c/0x168) >> [??? 4.148536] [<c053b258>] (deferred_probe_work_func) from >> [<c014352c>] (process_one_work+0x1d0/0x7bc) >> [??? 4.157644] [<c014352c>] (process_one_work) from [<c0143b84>] >> (worker_thread+0x34/0x4dc) >> [??? 4.165710] [<c0143b84>] (worker_thread) from [<c014a30c>] >> (kthread+0x128/0x164) >> [??? 4.173080] [<c014a30c>] (kthread) from [<c01010b4>] >> (ret_from_fork+0x14/0x20) >> [??? 4.180274] Exception stack(0xee13ffb0 to 0xee13fff8) >> [??? 4.185295] ffa0: 00000000 00000000 00000000 00000000 >> [??? 4.193466] ffc0: 00000000 00000000 00000000 00000000 00000000 >> 00000000 00000000 00000000 >> [??? 4.201620] ffe0: 00000000 00000000 00000000 00000000 00000013 >> 00000000 >> [??? 4.208207] Code: e2800e37 eafee601 e92d4070 e1a05000 (e59067d8) >> [??? 4.214370] ---[ end trace bf6046013df7cab2 ]--- >> >> This oops happens, because analogix_dp_bind() calls >> drm_dp_aux_register() >> which registers i2c adapter. I2C core tries to runtime get i2c host >> device during registration. This ends in analogix_dp_resume(), but dp >> context is NULL there. dp context is set in exynos_dp_bind() after >> executing analogix_dp_bind(). >> >> A quick workaround of this issue is to postpone enabling runtime PM >> on analogix device: >> >> diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c >> b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c >> index 8217c106c72b..db5a6b82815d 100644 >> --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c >> +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c >> @@ -1621,8 +1621,6 @@ analogix_dp_bind(struct device *dev, struct >> drm_device *drm_dev, >> ??????????????? return ERR_PTR(-ENODEV); >> ??????? } >> >> -?????? pm_runtime_enable(dev); >> - >> ??????? ret = devm_request_threaded_irq(&pdev->dev, dp->irq, >> ??????????????????????????????????????? analogix_dp_hardirq, >> ??????????????????????????????????????? analogix_dp_irq_thread, >> @@ -1642,7 +1640,9 @@ analogix_dp_bind(struct device *dev, struct >> drm_device *drm_dev, >> >> ??????? ret = drm_dp_aux_register(&dp->aux); >> ??????? if (ret) >> -?????????????? goto err_disable_pm_runtime; >> +?????????????? return ERR_PTR(ret); >> + >> +?????? pm_runtime_enable(dev); >> >> ??????? ret = analogix_dp_create_bridge(drm_dev, dp); >> ??????? if (ret) { >> >> With such patch Exynos based boards boot, but there is significant delay >> related to i2c/aux channel timeout: >> >> [??? 3.510610] [drm] Exynos DRM: using 14400000.fimd device for DMA >> mapping operations >> [??? 3.517733] exynos-drm exynos-drm: bound 14400000.fimd (ops >> fimd_component_ops) >> [??? 3.524483] exynos-drm exynos-drm: bound 14450000.mixer (ops >> mixer_component_ops) >> [??? 3.533743] exynos-drm exynos-drm: bound 145b0000.dp-controller >> (ops exynos_dp_ops) >> [??? 3.540074] exynos-drm exynos-drm: bound 14530000.hdmi (ops >> hdmi_component_ops) >> [??? 3.547262] [drm] Supports vblank timestamp caching Rev 2 >> (21.10.2013). >> [??? 3.553899] [drm] No driver support for vblank timestamp query. >> [??? 3.580467] exynos-dp 145b0000.dp-controller: AUX CH cmd reply >> timeout! >> [??? 4.085814] exynos-dp 145b0000.dp-controller: AUX CH enable timeout! >> [??? 4.590904] exynos-dp 145b0000.dp-controller: AUX CH enable timeout! >> [??? 5.095930] exynos-dp 145b0000.dp-controller: AUX CH enable timeout! >> [??? 5.601022] exynos-dp 145b0000.dp-controller: AUX CH enable timeout! >> [??? 6.106031] exynos-dp 145b0000.dp-controller: AUX CH enable timeout! >> [??? 6.611095] exynos-dp 145b0000.dp-controller: AUX CH enable timeout! >> [??? 7.116112] exynos-dp 145b0000.dp-controller: AUX CH enable timeout! >> [??? 7.621150] exynos-dp 145b0000.dp-controller: AUX CH enable timeout! >> [??? 8.126191] exynos-dp 145b0000.dp-controller: AUX CH enable timeout! >> [??? 8.638389] exynos-dp 145b0000.dp-controller: AUX CH enable timeout! >> [??? 9.138537] exynos-dp 145b0000.dp-controller: AUX CH enable timeout! >> [??? 9.638613] exynos-dp 145b0000.dp-controller: AUX CH enable timeout! >> [?? 10.138698] exynos-dp 145b0000.dp-controller: AUX CH enable timeout! >> [?? 10.638784] exynos-dp 145b0000.dp-controller: AUX CH enable timeout! >> [?? 11.138939] exynos-dp 145b0000.dp-controller: AUX CH enable timeout! >> [?? 11.639025] exynos-dp 145b0000.dp-controller: AUX CH enable timeout! >> [?? 12.139186] exynos-dp 145b0000.dp-controller: AUX CH enable timeout! >> [?? 12.639281] exynos-dp 145b0000.dp-controller: AUX CH enable timeout! >> [?? 13.139368] exynos-dp 145b0000.dp-controller: AUX CH enable timeout! >> [?? 13.216585] exynos-dp 145b0000.dp-controller: Link Training Clock >> Recovery success >> [?? 13.218846] exynos-dp 145b0000.dp-controller: Link Training success! >> [?? 13.333502] Console: switching to colour frame buffer device 170x48 >> [?? 13.446186] exynos-drm exynos-drm: fb0:? frame buffer device >> [?? 13.456751] [drm] Initialized exynos 1.0.0 20110530 for exynos-drm >> on minor 0 >> >> I've added some debugs and they reveal that AUX CH timeouts happen >> until DP >> PHY is powered on: >> >> [??? 3.511022] [drm] Exynos DRM: using 14400000.fimd device for DMA >> mapping operations >> [??? 3.518137] exynos-drm exynos-drm: bound 14400000.fimd (ops >> fimd_component_ops) >> [??? 3.524900] exynos-drm exynos-drm: bound 14450000.mixer (ops >> mixer_component_ops) >> [??? 3.533944] exynos-drm exynos-drm: bound 145b0000.dp-controller >> (ops exynos_dp_ops) >> [??? 3.540231] exynos-drm exynos-drm: bound 14530000.hdmi (ops >> hdmi_component_ops) >> [??? 3.547447] [drm] Supports vblank timestamp caching Rev 2 >> (21.10.2013). >> [??? 3.554077] [drm] No driver support for vblank timestamp query. >> [??? 3.580511] exynos-dp 145b0000.dp-controller: AUX CH cmd reply >> timeout! >> [??? 4.085882] exynos-dp 145b0000.dp-controller: AUX CH enable timeout! >> [??? 4.590979] exynos-dp 145b0000.dp-controller: AUX CH enable timeout! >> [??? 5.095986] exynos-dp 145b0000.dp-controller: AUX CH enable timeout! >> [??? 5.601057] exynos-dp 145b0000.dp-controller: AUX CH enable timeout! >> [??? 6.106110] exynos-dp 145b0000.dp-controller: AUX CH enable timeout! >> [??? 6.611168] exynos-dp 145b0000.dp-controller: AUX CH enable timeout! >> [??? 7.116212] exynos-dp 145b0000.dp-controller: AUX CH enable timeout! >> [??? 7.621290] exynos-dp 145b0000.dp-controller: AUX CH enable timeout! >> [??? 8.126331] exynos-dp 145b0000.dp-controller: AUX CH enable timeout! >> [??? 8.638578] exynos-dp 145b0000.dp-controller: AUX CH enable timeout! >> [??? 9.138715] exynos-dp 145b0000.dp-controller: AUX CH enable timeout! >> [??? 9.638872] exynos-dp 145b0000.dp-controller: AUX CH enable timeout! >> [?? 10.138963] exynos-dp 145b0000.dp-controller: AUX CH enable timeout! >> [?? 10.639057] exynos-dp 145b0000.dp-controller: AUX CH enable timeout! >> [?? 11.139208] exynos-dp 145b0000.dp-controller: AUX CH enable timeout! >> [?? 11.639374] exynos-dp 145b0000.dp-controller: AUX CH enable timeout! >> [?? 12.139451] exynos-dp 145b0000.dp-controller: AUX CH enable timeout! >> [?? 12.639553] exynos-dp 145b0000.dp-controller: AUX CH enable timeout! >> [?? 13.139636] exynos-dp 145b0000.dp-controller: AUX CH enable timeout! >> [?? 13.211826] analogix_dp_set_bridge line 1270 phy_power_on >> [?? 13.216999] exynos-dp 145b0000.dp-controller: Link Training Clock >> Recovery success >> [?? 13.219235] exynos-dp 145b0000.dp-controller: Link Training success! >> [?? 13.333802] Console: switching to colour frame buffer device 170x48 >> [?? 13.453198] exynos-drm exynos-drm: fb0:? frame buffer device >> [?? 13.462463] [drm] Initialized exynos 1.0.0 20110530 for exynos-drm >> on minor 0 >> >> It looks that handling of DDC i2c over DP AUX chanel (get_modes >> callback) is >> not synchronized with enabling bridge in analogix_dp_set_bridge(). >> >> I'm surprised that you didn't observe similar issues on rk3399. >> > > I've investigated this issue further and it turned out that the > DDC/I2C AUX > channel timeout issue is related to the fact, that exynos_dp driver > creates > additional connector for the display pipeline on Exynos5420 Chromebook2 > Peach-PIT. > > One connector is created by analogix_dp core, the second (the one > which is > in fact operational) is created by parade_ps eDP/LVDS bridge. The DDC/I2C > AUX channel timeouts happens when DRM core tries to get mode from the > connector object created by analogix_dp core. > > This patch fixes this issue: > > diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c > b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c > index db5a6b82815d..46b704adb2ae 100644 > --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c > +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c > @@ -1195,27 +1195,30 @@ static int analogix_dp_bridge_attach(struct > drm_bridge *bridge) > ?{ > ???? struct analogix_dp_device *dp = bridge->driver_private; > ???? struct drm_encoder *encoder = dp->encoder; > -??? struct drm_connector *connector = &dp->connector; > -??? int ret; > +??? struct drm_connector *connector = NULL; > +??? int ret = 0; > > ???? if (!bridge->encoder) { > ???? ??? DRM_ERROR("Parent encoder object not found"); > ???? ??? return -ENODEV; > ???? } > > -??? connector->polled = DRM_CONNECTOR_POLL_HPD; > +??? if (!dp->plat_data->skip_connector) { > +??? ??? connector = &dp->connector; > +??? ??? connector->polled = DRM_CONNECTOR_POLL_HPD; > > -??? ret = drm_connector_init(dp->drm_dev, connector, > -??? ??? ??? ??? ?&analogix_dp_connector_funcs, > -??? ??? ??? ??? ?DRM_MODE_CONNECTOR_eDP); > -??? if (ret) { > -??? ??? DRM_ERROR("Failed to initialize connector with drm\n"); > -??? ??? return ret; > -??? } > +??? ??? ret = drm_connector_init(dp->drm_dev, connector, > +??? ??? ??? ??? ??? ?&analogix_dp_connector_funcs, > +??? ??? ??? ??? ??? ?DRM_MODE_CONNECTOR_eDP); > +??? ??? if (ret) { > +??? ??? ??? DRM_ERROR("Failed to initialize connector with drm\n"); > +??? ??? ??? return ret; > +??? ??? } > > -??? drm_connector_helper_add(connector, > -??? ??? ??? ??? ?&analogix_dp_connector_helper_funcs); > -??? drm_mode_connector_attach_encoder(connector, encoder); > +??? ??? drm_connector_helper_add(connector, > +??? ??? ??? ??? ??? ?&analogix_dp_connector_helper_funcs); > +??? ??? drm_mode_connector_attach_encoder(connector, encoder); > +??? } > > ???? /* > ???? ?* NOTE: the connector registration is implemented in analogix > diff --git a/drivers/gpu/drm/exynos/exynos_dp.c > b/drivers/gpu/drm/exynos/exynos_dp.c > index b316249a3f89..86330f396784 100644 > --- a/drivers/gpu/drm/exynos/exynos_dp.c > +++ b/drivers/gpu/drm/exynos/exynos_dp.c > @@ -244,6 +244,7 @@ static int exynos_dp_probe(struct platform_device > *pdev) > > ???? /* The remote port can be either a panel or a bridge */ > ???? dp->plat_data.panel = panel; > +??? dp->plat_data.skip_connector = !!bridge; > ???? dp->ptn_bridge = bridge; > > ?out: > diff --git a/include/drm/bridge/analogix_dp.h > b/include/drm/bridge/analogix_dp.h > index b384f7e8d14a..475b706b49de 100644 > --- a/include/drm/bridge/analogix_dp.h > +++ b/include/drm/bridge/analogix_dp.h > @@ -31,6 +31,7 @@ struct analogix_dp_plat_data { > ???? struct drm_panel *panel; > ???? struct drm_encoder *encoder; > ???? struct drm_connector *connector; > +??? bool skip_connector; > > ???? int (*power_on_start)(struct analogix_dp_plat_data *); > ???? int (*power_on_end)(struct analogix_dp_plat_data *); > -- > > I'm still not convinced that the get_modes callback implementation and > real > DDC/I2C AUX transfers are correctly handled in ExynosDP case, but I > don't have > access to the hardware which would use them. Both Chromebook2 > Peach-PIT and > Chromebook Snow have additional bridge between analogix_dp and the panel. > > Frankly speaking, this issue reveals that the whole bridge-to-bridge, > connector, panel pipeline handling in the DRM drivers is a > over-complicated > (over-engineered?) and there is a mess in the drivers. There is one more issue even after above patch - disabling display pipeline causes system hang. I've spent some more time debugging it and found that the power off sequence in analogix_dp_bridge_disable() is incorrect. In case of exynos_dp, external PHY also powers analogix_dp block, so any register access after phy_power_off() is forbidden. The following patch fixes this issue: diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c index ad8737384ab0..32c42d33c25e 100644 --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c @@ -1349,8 +1349,8 @@ static void analogix_dp_bridge_disable(struct drm_bridge *bridge) ???? if (dp->plat_data->power_off) ???? ??? dp->plat_data->power_off(dp->plat_data); -??? phy_power_off(dp->phy); ???? analogix_dp_set_analog_power_down(dp, POWER_ALL, 1); +??? phy_power_off(dp->phy); ???? clk_disable_unprepare(dp->clock); With the above patch it looks that exynos_dp is now fully operational again. Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland
