From: zain wang wzz@rock-chips.com

The bridge does not need to be powered in analogix_dp_bind(), so remove the calls to pm_runtime_get()/phy_power_on()/analogix_dp_init_dp() as well as their power-off counterparts.

Cc: Stéphane Marchesin marcheu@chromium.org Signed-off-by: zain wang wzz@rock-chips.com Signed-off-by: Caesar Wang wxt@rock-chips.com [the patch originally just removed the power_on portion, seanpaul removed the power off code as well as improved the commit message] Signed-off-by: Sean Paul seanpaul@chromium.org Signed-off-by: Thierry Escande thierry.escande@collabora.com Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com --- drivers/gpu/drm/bridge/analogix/analogix_dp_core.c | 10 ---------- 1 file changed, 10 deletions(-)

diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c index 3f7a796b27e4..8475749baae5 100644 --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c @@ -1378,11 +1378,6 @@ analogix_dp_bind(struct device *dev, struct drm_device *drm_dev,

pm_runtime_enable(dev);

- pm_runtime_get_sync(dev); - phy_power_on(dp->phy); - - analogix_dp_init_dp(dp); - ret = devm_request_threaded_irq(&pdev->dev, dp->irq, analogix_dp_hardirq, analogix_dp_irq_thread, @@ -1410,15 +1405,10 @@ analogix_dp_bind(struct device *dev, struct drm_device *drm_dev, goto err_disable_pm_runtime; }

- phy_power_off(dp->phy); - pm_runtime_put(dev); - return dp;

err_disable_pm_runtime:

- phy_power_off(dp->phy); - pm_runtime_put(dev); pm_runtime_disable(dev);

return ERR_PTR(ret);

Enabling runtime power management early in analogix_dp_bind() causes following kernel NULL pointer dereference:

Unable to handle kernel NULL pointer dereference at virtual address 000007d8 pgd = 28ffa2e4 [000007d8] *pgd=00000000 Internal error: Oops: 5 [#1] PREEMPT SMP ARM Modules linked in: CPU: 6 PID: 69 Comm: kworker/6:1 Not tainted 4.16.0-rc1-00062-ge25751974ba8 #3622 Hardware name: SAMSUNG EXYNOS (Flattened Device Tree) Workqueue: events deferred_probe_work_func PC is at analogix_dp_resume+0x8/0xc0 LR is at pm_generic_runtime_resume+0x2c/0x38 pc : [<c0531b98>] lr : [<c0543fec>] psr: a0000113 sp : ee13fbd8 ip : 0000001a fp : 00000001 r10: ee0eb080 r9 : c0552bd8 r8 : c0fb1d98 r7 : eebb1010 r6 : eeae9808 r5 : 00000000 r4 : d4850415 r3 : ee0ed010 r2 : b2d05e00 r1 : 00000000 r0 : 00000000 Flags: NzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Control: 10c5387d Table: 2000406a DAC: 00000051 Process kworker/6:1 (pid: 69, stack limit = 0x913205b4) Stack: (0xee13fbd8 to 0xee140000) ... [<c0531b98>] (analogix_dp_resume) from [<c0543fec>] (pm_generic_runtime_resume+0x2c/0x38) [<c0543fec>] (pm_generic_runtime_resume) from [<c054ffb4>] (__genpd_runtime_resume+0x2c/0x8c) [<c054ffb4>] (__genpd_runtime_resume) from [<c0552d24>] (genpd_runtime_resume+0x14c/0x258) [<c0552d24>] (genpd_runtime_resume) from [<c0547798>] (__rpm_callback+0x134/0x214) [<c0547798>] (__rpm_callback) from [<c0547898>] (rpm_callback+0x20/0x80) [<c0547898>] (rpm_callback) from [<c0546ff4>] (rpm_resume+0x3a0/0x734) [<c0546ff4>] (rpm_resume) from [<c05475ec>] (__pm_runtime_resume+0x64/0x9c) [<c05475ec>] (__pm_runtime_resume) from [<c053b95c>] (__device_attach+0x8c/0x134) [<c053b95c>] (__device_attach) from [<c053ad08>] (bus_probe_device+0x88/0x90) [<c053ad08>] (bus_probe_device) from [<c05390d0>] (device_add+0x3a8/0x580) [<c05390d0>] (device_add) from [<c06764c4>] (i2c_register_adapter+0xd4/0x3ec) [<c06764c4>] (i2c_register_adapter) from [<c05321c8>] (analogix_dp_bind+0x2a0/0x410) [<c05321c8>] (analogix_dp_bind) from [<c0528e90>] (exynos_dp_bind+0x9c/0x12c) [<c0528e90>] (exynos_dp_bind) from [<c0535bc4>] (component_bind_all+0xfc/0x258) [<c0535bc4>] (component_bind_all) from [<c0522ee8>] (exynos_drm_bind+0x15c/0x28c) [<c0522ee8>] (exynos_drm_bind) from [<c0536378>] (try_to_bring_up_master+0x1b8/0x29c) [<c0536378>] (try_to_bring_up_master) from [<c05364fc>] (component_add+0xa0/0x170) [<c05364fc>] (component_add) from [<c0528fe4>] (exynos_dp_probe+0x64/0xb8) [<c0528fe4>] (exynos_dp_probe) from [<c053debc>] (platform_drv_probe+0x50/0xb0) [<c053debc>] (platform_drv_probe) from [<c053bd18>] (driver_probe_device+0x2b8/0x4a0) [<c053bd18>] (driver_probe_device) from [<c0539e4c>] (bus_for_each_drv+0x44/0x8c) [<c0539e4c>] (bus_for_each_drv) from [<c053b970>] (__device_attach+0xa0/0x134) [<c053b970>] (__device_attach) from [<c053ad08>] (bus_probe_device+0x88/0x90) [<c053ad08>] (bus_probe_device) from [<c053b258>] (deferred_probe_work_func+0x3c/0x168) [<c053b258>] (deferred_probe_work_func) from [<c014352c>] (process_one_work+0x1d0/0x7bc) [<c014352c>] (process_one_work) from [<c0143b84>] (worker_thread+0x34/0x4dc) [<c0143b84>] (worker_thread) from [<c014a30c>] (kthread+0x128/0x164) [<c014a30c>] (kthread) from [<c01010b4>] (ret_from_fork+0x14/0x20) Exception stack(0xee13ffb0 to 0xee13fff8) ffa0: 00000000 00000000 00000000 00000000 ffc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 ffe0: 00000000 00000000 00000000 00000000 00000013 00000000 Code: e2800e37 eafee601 e92d4070 e1a05000 (e59067d8) ---[ 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(). Fix this issue by postponing enabling runtime power management after drm_dp_aux_register().

Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com --- drivers/gpu/drm/bridge/analogix/analogix_dp_core.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c index 8475749baae5..b391d149db91 100644 --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c @@ -1376,8 +1376,6 @@ 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, @@ -1397,7 +1395,9 @@ 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) {

If there is another bridge after analogix_dp, then the connector object should not be created. This fixes following timeouts on Exynos5420-based Chromebook2 Peach-PIT board during boot:

exynos-dp 145b0000.dp-controller: AUX CH cmd reply timeout! exynos-dp 145b0000.dp-controller: AUX CH enable timeout! exynos-dp 145b0000.dp-controller: AUX CH enable timeout! exynos-dp 145b0000.dp-controller: AUX CH enable timeout! exynos-dp 145b0000.dp-controller: AUX CH enable timeout!

Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com --- drivers/gpu/drm/bridge/analogix/analogix_dp_core.c | 29 ++++++++++++---------- drivers/gpu/drm/exynos/exynos_dp.c | 1 + include/drm/bridge/analogix_dp.h | 1 + 3 files changed, 18 insertions(+), 13 deletions(-)

diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c index b391d149db91..a693ab3078f0 100644 --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c @@ -1012,27 +1012,30 @@ 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 33319a858f3a..964831dab102 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 5518fc75dd6e..711fff9b6803 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)(struct analogix_dp_plat_data *); int (*power_off)(struct analogix_dp_plat_data *);