Hi Hans,
On Tue, Aug 27, 2019 at 12:51:08PM +0300, Laurent Pinchart wrote:
> On Tue, Aug 27, 2019 at 11:07:56AM +0200, Hans Verkuil wrote:
> > Hi Laurent,
> >
> > I tried this series with my Pandaboard, but it broke my Pandaboard. After
> > doing a git bisect it ended up with this patch as the culprit.
> >
> > If I boot my Pandaboard I get this:
> >
> > [ 3.271881] omapdss_dss 58000000.dss: 58000000.dss supply vdda_video not
> > found, using dummy regulator
> > [ 3.285369] omapdss_dss 58000000.dss: 58000000.dss supply vdda_video not
> > found, using dummy regulator
> > [ 24.286773] rcu: INFO: rcu_sched self-detected stall on CPU
> > [ 24.292388] rcu: 0-...!: (1306 ticks this GP) idle=6b6/1/0x40000002
> > softirq=85/85 fqs=19
> > [ 24.300689] (t=2100 jiffies g=-1063 q=10)
> > [ 24.304809] rcu: rcu_sched kthread starved for 2058 jiffies! g-1063 f0x0
> > RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=1
> > [ 24.315124] rcu: RCU grace-period kthread stack dump:
> > [ 24.315124] rcu_sched I 0 10 2 0x00000000
> > [ 24.325805] [<c09b7130>] (__schedule) from [<c09b73a8>]
> > (schedule+0x40/0xc0)
> > [ 24.332885] [<c09b73a8>] (schedule) from [<c09ba9d0>]
> > (schedule_timeout+0x174/0x2a8)
> > [ 24.340698] [<c09ba9d0>] (schedule_timeout) from [<c01943a4>]
> > (rcu_gp_kthread+0x49c/0x9f4)
> > [ 24.349121] [<c01943a4>] (rcu_gp_kthread) from [<c01559f8>]
> > (kthread+0x13c/0x148)
> > [ 24.356658] [<c01559f8>] (kthread) from [<c01010e8>]
> > (ret_from_fork+0x14/0x2c)
> > [ 24.363922] Exception stack(0xe70a1fb0 to 0xe70a1ff8)
> > [ 24.363922] 1fa0: 00000000 00000000
> > 00000000 00000000
> > [ 24.363922] 1fc0: 00000000 00000000 00000000 00000000 00000000 00000000
> > 00000000 00000000
> > [ 24.385437] 1fe0: 00000000 00000000 00000000 00000000 00000013 00000000
> > [ 24.392089] NMI backtrace for cpu 0
> > [ 24.392120] CPU: 0 PID: 105 Comm: kworker/0:2 Not tainted 5.3.0-rc3-arm
> > #152
> > [ 24.392120] Hardware name: Generic OMAP4 (Flattened Device Tree)
> > [ 24.408721] Workqueue: events deferred_probe_work_func
> > [ 24.408721] [<c010fd70>] (unwind_backtrace) from [<c010b7e8>]
> > (show_stack+0x10/0x14)
> > [ 24.421783] [<c010b7e8>] (show_stack) from [<c09a054c>]
> > (dump_stack+0x84/0x9c)
> > [ 24.429077] [<c09a054c>] (dump_stack) from [<c09a6ecc>]
> > (nmi_cpu_backtrace+0x8c/0xc0)
> > [ 24.436950] [<c09a6ecc>] (nmi_cpu_backtrace) from [<c09a7014>]
> > (nmi_trigger_cpumask_backtrace+0x114/0x12c)
> > [ 24.446655] [<c09a7014>] (nmi_trigger_cpumask_backtrace) from
> > [<c01961e0>] (rcu_dump_cpu_stacks+0xa4/0xcc)
> > [ 24.456359] [<c01961e0>] (rcu_dump_cpu_stacks) from [<c01952bc>]
> > (rcu_sched_clock_irq+0x608/0x7f8)
> > [ 24.465362] [<c01952bc>] (rcu_sched_clock_irq) from [<c019b21c>]
> > (update_process_times+0x34/0x6c)
> > [ 24.465362] [<c019b21c>] (update_process_times) from [<c01acfcc>]
> > (tick_sched_timer+0x4c/0xa8)
> > [ 24.483001] [<c01acfcc>] (tick_sched_timer) from [<c019c470>]
> > (__hrtimer_run_queues+0x154/0x1fc)
> > [ 24.491851] [<c019c470>] (__hrtimer_run_queues) from [<c019c84c>]
> > (hrtimer_interrupt+0x11c/0x2ac)
> > [ 24.500762] [<c019c84c>] (hrtimer_interrupt) from [<c010f3ac>]
> > (twd_handler+0x30/0x38)
> > [ 24.500762] [<c010f3ac>] (twd_handler) from [<c018959c>]
> > (handle_percpu_devid_irq+0x78/0x138)
> > [ 24.517333] [<c018959c>] (handle_percpu_devid_irq) from [<c0183a60>]
> > (generic_handle_irq+0x24/0x34)
> > [ 24.526458] [<c0183a60>] (generic_handle_irq) from [<c0184028>]
> > (__handle_domain_irq+0x5c/0xb4)
> > [ 24.526458] [<c0184028>] (__handle_domain_irq) from [<c03bbf2c>]
> > (gic_handle_irq+0x58/0x9c)
> > [ 24.526458] [<c03bbf2c>] (gic_handle_irq) from [<c0101a8c>]
> > (__irq_svc+0x6c/0x90)
> > [ 24.526458] Exception stack(0xe6439d68 to 0xe6439db0)
> > [ 24.551177] 9d60: c0f783e8 00000000 00000000 efdb49d0
> > e647f2e8 efdb7f74
> > [ 24.551177] 9d80: e647f2e8 00000000 e647f294 e647f2e8 00000000 efdb5a98
> > 00000000 e6439db8
> > [ 24.551177] 9da0: c04e9830 c04e9858 20000153 ffffffff
> > [ 24.577789] [<c0101a8c>] (__irq_svc) from [<c04e9858>]
> > (of_drm_find_bridge+0x40/0x84)
> > [ 24.577789] [<c04e9858>] (of_drm_find_bridge) from [<c0526608>]
> > (omapdss_device_init_output+0x38/0x140)
> > [ 24.595153] [<c0526608>] (omapdss_device_init_output) from [<c0530294>]
> > (dpi_init_port+0x208/0x294)
> > [ 24.604248] [<c0530294>] (dpi_init_port) from [<c05278c4>]
> > (dss_probe+0x2b4/0x550)
> > [ 24.604248] [<c05278c4>] (dss_probe) from [<c0576c1c>]
> > (platform_drv_probe+0x48/0x98)
> > [ 24.604248] [<c0576c1c>] (platform_drv_probe) from [<c0574eb0>]
> > (really_probe+0xf0/0x2c4)
> > [ 24.627990] [<c0574eb0>] (really_probe) from [<c057520c>]
> > (driver_probe_device+0x60/0x168)
> > [ 24.627990] [<c057520c>] (driver_probe_device) from [<c0573410>]
> > (bus_for_each_drv+0x84/0xc8)
> > [ 24.644866] [<c0573410>] (bus_for_each_drv) from [<c0574d4c>]
> > (__device_attach+0xd4/0x140)
> > [ 24.644866] [<c0574d4c>] (__device_attach) from [<c05740f8>]
> > (bus_probe_device+0x84/0x8c)
> > [ 24.661376] [<c05740f8>] (bus_probe_device) from [<c057456c>]
> > (deferred_probe_work_func+0x64/0x90)
> > [ 24.670379] [<c057456c>] (deferred_probe_work_func) from [<c014f960>]
> > (process_one_work+0x204/0x41c)
> > [ 24.670410] [<c014f960>] (process_one_work) from [<c01510d4>]
> > (worker_thread+0x2a8/0x5bc)
> > [ 24.687805] [<c01510d4>] (worker_thread) from [<c01559f8>]
> > (kthread+0x13c/0x148)
> > [ 24.687805] [<c01559f8>] (kthread) from [<c01010e8>]
> > (ret_from_fork+0x14/0x2c)
> > [ 24.702484] Exception stack(0xe6439fb0 to 0xe6439ff8)
> > [ 24.702484] 9fa0: 00000000 00000000
> > 00000000 00000000
> > [ 24.702484] 9fc0: 00000000 00000000 00000000 00000000 00000000 00000000
> > 00000000 00000000
> > [ 24.723999] 9fe0: 00000000 00000000 00000000 00000000 00000013 00000000
> >
> > I can send my .config upon request if needed.
> >
> > CONFIG_OMAP2_DSS_DPI is 'y', but there is nothing connected to the DPI port.
>
> I've retested this on my pandaboard and couldn't reproduce the issue. As
> I suspected a problem related to the kernel configuration, I tried
> building the drivers in the kernel image instead of using modules, and I
> then got a similar looking crash. I'm investigating it now.
Fix pushed to
git://linuxtv.org/pinchartl/media.git omapdrm/bridge/devel
The issue was caused by incorrect cleanup on probe deferral, fixed by a
combination of "drm/omap: dss: Cleanup DSS ports on initialisation
failure" (new patch) and changes to "drm/omap: dpi: Register a
drm_bridge" and "drm/omap: spi: Register a drm_bridge".
--
Regards,
Laurent Pinchart
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