On Fri, Dec 30, 2016 at 4:57 AM, Marek Szyprowski <m.szyprowski@xxxxxxxxxxx> wrote: > Analogix_dp_bind() can be called from component framework, which doesn't > guarantee proper runtime PM state of the device during bind operation, > so ensure that device is runtime active before doing any register access. > This ensures that the power domain, to which DP module belongs, is turned > on. While at it, also fix the unbalanced call to phy_power_on() in > analogix_dp_bind() function. > > This patch solves the following kernel oops on Samsung Exynos5250 Snow > board: > > Unhandled fault: imprecise external abort (0x406) at 0x00000000 > pgd = c0004000 > [00000000] *pgd=00000000 > Internal error: : 406 [#1] PREEMPT SMP ARM > Modules linked in: > CPU: 0 PID: 75 Comm: kworker/0:2 Not tainted 4.9.0 #1046 > Hardware name: SAMSUNG EXYNOS (Flattened Device Tree) > Workqueue: events deferred_probe_work_func > task: ee272300 task.stack: ee312000 > PC is at analogix_dp_enable_sw_function+0x18/0x2c > LR is at analogix_dp_init_dp+0x2c/0x50 > ... > [<c03fcb38>] (analogix_dp_enable_sw_function) from [<c03fa9c4>] (analogix_dp_init_dp+0x2c/0x50) > [<c03fa9c4>] (analogix_dp_init_dp) from [<c03fab6c>] (analogix_dp_bind+0x184/0x42c) > [<c03fab6c>] (analogix_dp_bind) from [<c03fdb84>] (component_bind_all+0xf0/0x218) > [<c03fdb84>] (component_bind_all) from [<c03ed64c>] (exynos_drm_load+0x134/0x200) > [<c03ed64c>] (exynos_drm_load) from [<c03d5058>] (drm_dev_register+0xa0/0xd0) > [<c03d5058>] (drm_dev_register) from [<c03d66b8>] (drm_platform_init+0x58/0xb0) > [<c03d66b8>] (drm_platform_init) from [<c03fe0c4>] (try_to_bring_up_master+0x14c/0x188) > [<c03fe0c4>] (try_to_bring_up_master) from [<c03fe188>] (component_add+0x88/0x138) > [<c03fe188>] (component_add) from [<c0403a38>] (platform_drv_probe+0x50/0xb0) > [<c0403a38>] (platform_drv_probe) from [<c0402470>] (driver_probe_device+0x1f0/0x2a8) > [<c0402470>] (driver_probe_device) from [<c0400a54>] (bus_for_each_drv+0x44/0x8c) > [<c0400a54>] (bus_for_each_drv) from [<c04021f8>] (__device_attach+0x9c/0x100) > [<c04021f8>] (__device_attach) from [<c04018e8>] (bus_probe_device+0x84/0x8c) > [<c04018e8>] (bus_probe_device) from [<c0401d1c>] (deferred_probe_work_func+0x60/0x8c) > [<c0401d1c>] (deferred_probe_work_func) from [<c012fc14>] (process_one_work+0x120/0x318) > [<c012fc14>] (process_one_work) from [<c012fe34>] (process_scheduled_works+0x28/0x38) > [<c012fe34>] (process_scheduled_works) from [<c0130048>] (worker_thread+0x204/0x4ac) > [<c0130048>] (worker_thread) from [<c01352c4>] (kthread+0xd8/0xf4) > [<c01352c4>] (kthread) from [<c0107978>] (ret_from_fork+0x14/0x3c) > Code: e59035f0 e5935018 f57ff04f e3c55001 (f57ff04e) > ---[ end trace 3d1d0d87796de344 ]--- > Reviewed-by: Sean Paul <seanpaul@xxxxxxxxxxxx> > Signed-off-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx> > --- > drivers/gpu/drm/bridge/analogix/analogix_dp_core.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c > index eb9bf8786c24..18eefdcbf1ba 100644 > --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c > +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c > @@ -1382,6 +1382,7 @@ int 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); > @@ -1414,9 +1415,15 @@ int 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 0; > > err_disable_pm_runtime: > + > + phy_power_off(dp->phy); > + pm_runtime_put(dev); > pm_runtime_disable(dev); > > return ret; > -- > 1.9.1 > -- Sean Paul, Software Engineer, Google / Chromium OS -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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