Bug with omap3-isp - 30 seconds delay for probe success

[H. Nikolaus Schaller]

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Hi Tony,
I am observing an issue with omap3-isp for a while. It seems
to have started with v5.6 but I have preferred to invest some
time into analysis of the problem instead of trying a bisect.

The problem is that there is a

[   32.483703] WARNING: CPU: 0 PID: 2052 at drivers/base/dd.c:270 driver_deferred_probe_check_state+0x44/0x5c
[   32.498809] omap3isp 480bc000.isp: deferred probe timeout, ignoring dependency

from the driver, just after exactly 30 seconds. This is when
driver_deferred_probe_timeout had timed out (chaning driver_deferred_probe_timeout makes
it take more or less time).

So something is requested for by the omap3-isp driver which never becomes
available.

Some analysis shows that the omap3-isp is the only device calling of_iommu_xlate()
with a NULL opp table which ends up in driver_deferred_probe_check_state() to return
-EPROBE_DEFER until 30 seconds have passed.

Well, it seems to be resonable that there are no ops returned by iommu_ops_from_fwnode()
since there is no firmware for the ISP. But there should be no timeout.

This of_iommu_xlate() is called from of_iommu_configure() in the loop to handle
all "iommus" references. There is one for omap34xx and omap36xx.dtsi and the mmu_isp
is defined in omap3.dtsi. They refer to compatible = "ti,omap2-iommu"; and
ti,hwmods = "mmu_isp";

Are there any ideas what in the iommu or hwmods or firmware loading for the mmu_isp
may have changed recently?

Anyways the omap3-isp seems to be initialized after this 30 seconds timeout and
responds to media-ctl.

A more complete log attached.

BR,
Nikolaus


[   32.478759] ------------[ cut here ]------------
[   32.483703] WARNING: CPU: 0 PID: 2052 at drivers/base/dd.c:270 driver_deferred_probe_check_state+0x44/0x5c
[   32.498809] omap3isp 480bc000.isp: deferred probe timeout, ignoring dependency
[   32.498840] Modules linked in: omapdrm libertas_sdio libertas cfg80211 panel_tpo_td028ttec1 snd_soc_simple_card snd_soc_simple_card_utils snd_soc_omap_twl4030 simple_bridge wwan_on_off pvrsrvkm_omap3630_sgx530_125 snd_soc_gtm601 pwm_omap_dmtimer omap_aes_driver crypto_engine omap_crypto omap_sham omap3_isp videobuf2_dma_contig videobuf2_memops videobuf2_v4l2 videobuf2_common bq27xxx_battery_hdq bq27xxx_battery omap_hdq omap2430 bmp280_spi bmp280_i2c itg3200 bmp280 at24 tsc2007 leds_tca6507 bma180 phy_twl4030_usb musb_hdrc twl4030_pwrbutton hci_uart snd_soc_twl4030 twl4030_vibra btbcm ov9655 twl4030_madc v4l2_fwnode twl4030_charger videodev hmc5843_i2c bluetooth hmc5843_core gnss_sirf industrialio_triggered_buffer mc kfifo_buf ecdh_generic snd_soc_si47xx ecc gnss snd_soc_omap_mcbsp snd_soc_ti_sdma ehci_omap omapdss omapdss_base drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops cec display_connector generic_adc_battery drm industrialio drm_panel_orientation_quirks input_polldev
[   32.509704]  pwm_bl ip_tables x_tables ipv6 nf_defrag_ipv6 autofs4
[   32.612792] CPU: 0 PID: 2052 Comm: kworker/0:5 Not tainted 5.7.0-rc4-letux+ #2570
[   32.620758] Hardware name: Generic OMAP36xx (Flattened Device Tree)
[   32.627471] Workqueue: events deferred_probe_work_func
[   32.632995] [<c010f1f4>] (unwind_backtrace) from [<c010a7c8>] (show_stack+0x10/0x14)
[   32.641235] [<c010a7c8>] (show_stack) from [<c047d3c4>] (dump_stack+0x88/0xa8)
[   32.648925] [<c047d3c4>] (dump_stack) from [<c01304f0>] (__warn+0xc8/0xf4)
[   32.656249] [<c01304f0>] (__warn) from [<c013058c>] (warn_slowpath_fmt+0x70/0x9c)
[   32.664215] [<c013058c>] (warn_slowpath_fmt) from [<c056fa44>] (driver_deferred_probe_check_state+0x44/0x5c)
[   32.674652] [<c056fa44>] (driver_deferred_probe_check_state) from [<c05641d4>] (of_iommu_configure+0x98/0x1b4)
[   32.685302] [<c05641d4>] (of_iommu_configure) from [<c06dd6cc>] (of_dma_configure+0x1d8/0x234)
[   32.694458] [<c06dd6cc>] (of_dma_configure) from [<c056fc6c>] (really_probe+0x104/0x324)
[   32.703063] [<c056fc6c>] (really_probe) from [<c05700dc>] (driver_probe_device+0x10c/0x154)
[   32.711944] [<c05700dc>] (driver_probe_device) from [<c056e3a8>] (bus_for_each_drv+0x90/0xb8)
[   32.721008] [<c056e3a8>] (bus_for_each_drv) from [<c056ff1c>] (__device_attach+0x90/0x120)
[   32.729797] [<c056ff1c>] (__device_attach) from [<c056efdc>] (bus_probe_device+0x28/0x80)
[   32.738494] [<c056efdc>] (bus_probe_device) from [<c056f464>] (deferred_probe_work_func+0x5c/0x80)
[   32.748016] [<c056f464>] (deferred_probe_work_func) from [<c014986c>] (process_one_work+0x1e4/0x394)
[   32.757720] [<c014986c>] (process_one_work) from [<c0149a44>] (process_scheduled_works+0x28/0x30)
[   32.767150] [<c0149a44>] (process_scheduled_works) from [<c0149f38>] (worker_thread+0x210/0x2d8)
[   32.776489] [<c0149f38>] (worker_thread) from [<c014e7cc>] (kthread+0x138/0x148)
[   32.784362] [<c014e7cc>] (kthread) from [<c0100148>] (ret_from_fork+0x14/0x2c)
[   32.792022] Exception stack(0xda649fb0 to 0xda649ff8)
[   32.797393] 9fa0:                                     00000000 00000000 00000000 00000000
[   32.806091] 9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[   32.814788] 9fe0: 00000000 00000000 00000000 00000000 00000013 00000000
[   32.842346] omap3isp 480bc000.isp: supply vdd-csiphy1 not found, using dummy regulator
[   32.855133] omap3isp 480bc000.isp: supply vdd-csiphy2 not found, using dummy regulator
[   32.864746] omap3isp 480bc000.isp: Revision 15.0 found
[   32.870971] omap-iommu 480bd400.mmu: 480bd400.mmu: version 1.1
[   32.879913] omap3isp 480bc000.isp: Entity type for entity OMAP3 ISP CCP2 was not initialized!
[   32.897247] omap3isp 480bc000.isp: Entity type for entity OMAP3 ISP CSI2a was not initialized!
[   32.917999] omap3isp 480bc000.isp: Entity type for entity OMAP3 ISP CCDC was not initialized!
[   32.938446] omap3isp 480bc000.isp: Entity type for entity OMAP3 ISP preview was not initialized!
[   32.966888] omap3isp 480bc000.isp: Entity type for entity OMAP3 ISP resizer was not initialized!
[   32.987548] omap3isp 480bc000.isp: Entity type for entity OMAP3 ISP AEWB was not initialized!
[   33.010803] omap3isp 480bc000.isp: Entity type for entity OMAP3 ISP AF was not initialized!
[   33.026519] omap3isp 480bc000.isp: Entity type for entity OMAP3 ISP histogram was not initialized!
[   33.052062] ov9655 1-0030: ov9655_probe
[   33.064910] ov9655 1-0030: supply dvdd not found, using dummy regulator
[   33.075714] ov9655 1-0030: supply dovdd not found, using dummy regulator
[   33.097900] ov9655 1-0030: __ov9655_set_power on=1
[   33.206787] ov9655 1-0030: OV9655 read register 1c : 7f
[   33.212707] ov9655 1-0030: OV9655 read register 1d : a2
[   33.220336] ov9655 1-0030: OV9655 read register 0a : 96
[   33.226104] ov9655 1-0030: OV9655 read register 0b : 57
[   33.231872] ov9655 1-0030: __ov9655_set_power on=0
[   33.238586] ov9655 1-0030: OV9655 REV5 detected at address 0x30
[   33.258605] platform sound_bluetooth: deferred probe pending
[   35.915588] omap-iommu 480bd400.mmu: 480bd400.mmu: version 1.1
[   36.040069] ov9655 1-0030: ov9655_open