[Letux-kernel] omap-gpmc gta04 regression 4.7-rc1

[Roger Quadros]

On 07/06/16 10:18, Roger Quadros wrote:
> Hi Marek,
> 
> On 07/06/16 09:06, Tony Lindgren wrote:
>> Hi,
>>
>> * Belisko Marek <marek.belisko at gmail.com> [160605 02:50]:
>>> Hi Tony,
>>>
>>> we're experiencing crash on gta04 after updating to 4.7-rc1. Crash is:
>>>
>>> [    4.045166] Unable to handle kernel NULL pointer dereference at
>>> virtual address 0000006c
>>> [    4.053619] pgd = c0004000
>>> [    4.056457] [0000006c] *pgd=00000000
>>> [    4.060211] Internal error: Oops: 5 [#1] PREEMPT SMP ARM
>>> [    4.065795] Modules linked in:
>>> [    4.069000] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.7.0-rc1-letux+ #351
>>> [    4.076263] Hardware name: Generic OMAP36xx (Flattened Device Tree)
>>> [    4.082824] task: dd8b6d80 ti: dd8b8000 task.ti: dd8b8000
>>> [    4.088470] PC is at of_gpiochip_find_and_xlate+0x4/0x70
>>> [    4.094024] LR is at gpiochip_find+0x3c/0x70
>>> [    4.098510] pc : [<c0423570>]    lr : [<c041f348>]    psr: 20000093
>>> [    4.098510] sp : dd8b9d50  ip : df9adc20  fp : 00000000
>>> [    4.110504] r10: c0a50858  r9 : 00000007  r8 : c042356c
>>> [    4.115936] r7 : dd8b9d80  r6 : 60000013  r5 : c0b5efb8  r4 : dda44800
>>> [    4.122772] r3 : dda44abc  r2 : 00000000  r1 : dd8b9d80  r0 : 00000000
>>> [    4.129608] Flags: nzCv  IRQs off  FIQs on  Mode SVC_32  ISA ARM
>>> Segment none
>>> [    4.137145] Control: 10c5387d  Table: 80004019  DAC: 00000051
>>> [    4.143157] Process swapper/0 (pid: 1, stack limit = 0xdd8b8218)
>>> [    4.149444] Stack: (0xdd8b9d50 to 0xdd8ba000)
>>> [    4.153991] 9d40:                                     dda44abc
>>> dda44800 c0b5efb8 c041f348
>>> [    4.162536] 9d60: dd8b9df4 00000000 dd8b9df8 df9c2940 00000000
>>> c04236ac dd8b9d84 dd8b9dfe
>>> [    4.171112] 9d80: dd8b9df4 df9b2cd4 00000002 00000000 00000001
>>> 00000000 00000000 00000000
>>> [    4.179656] 9da0: 00000000 00000000 00000000 00000000 00000000
>>> 00000000 00000000 00000000
>>> [    4.188201] 9dc0: 00000000 00000000 00000000 fffffdfb dd8b9df8
>>> 00000000 c0730f08 dda61c10
>>> [    4.196746] 9de0: c088c0f6 c0422958 c08e8f80 c0b9b533 ddd75440
>>> 00000000 65736572 70672d74
>>> [    4.205291] 9e00: 00736f69 70672d74 00736f69 c0246c14 dd8b6d80
>>> 00000007 00000001 ddd75440
>>> [    4.213867] 9e20: 00000001 dda61c10 dda61c10 c088c0f6 00000007
>>> c0422bd0 ffffffff 00000007
>>> [    4.222412] 9e40: ddd75490 dda61c10 c088c0f6 c1364aa4 00000000
>>> c041ecac ddd75480 ddd754d0
>>> [    4.230957] 9e60: dda61c10 dda61c00 c0b7dfcc c0593324 c05932d0
>>> dda61c10 c0b7dfcc c0481c08
>>> [    4.239501] 9e80: dda61c10 c1364a9c 00000000 c047fce8 00000000
>>> dda61c10 dda61c44 c0b7dfcc
>>> [    4.248046] 9ea0: c0b67c60 c0b9e4c0 c0b9e4c0 c047fed8 00000000
>>> c0b7dfcc c047fe50 c047e3b8
>>> [    4.256622] 9ec0: dd899aa4 dda3a1d0 c0b7dfcc 00000000 ddd72180
>>> c047f398 c08e2ef2 dd8b7310
>>> [    4.265167] 9ee0: 00000000 c0b7dfcc c0a3b71c 00000000 c0a6a668
>>> c0480e28 c04816e0 00000006
>>> [    4.273712] 9f00: c0a3b71c c010192c 00000073 dd8b9f28 c0150f40
>>> c03f3694 60000000 ffffffff
>>> [    4.282257] 9f20: 00000051 c0b9e4c0 000000b0 df97c1ae 00000000
>>> c01510d4 c0934738 00000006
>>> [    4.290802] 9f40: 00000006 c093550c 000000b0 c093550c c0a50834
>>> 00000006 c0a5084c 00000006
>>> [    4.299377] 9f60: c0a50850 000000b1 c0a6a668 c0b9e4c0 c0b9e4c0
>>> c0a00d78 00000006 00000006
>>> [    4.307922] 9f80: 00000000 c0a00598 00000000 c06ced10 00000000
>>> 00000000 00000000 00000000
>>> [    4.316467] 9fa0: 00000000 c06ced18 00000000 c01070d0 00000000
>>> 00000000 00000000 00000000
>>> [    4.325012] 9fc0: 00000000 00000000 00000000 00000000 00000000
>>> 00000000 00000000 00000000
>>> [    4.333557] 9fe0: 00000000 00000000 00000000 00000000 00000013
>>> 00000000 01000000 00040040
>>> [    4.342132] [<c0423570>] (of_gpiochip_find_and_xlate) from
>>> [<c041f348>] (gpiochip_find+0x3c/0x70)
>>> [    4.351409] [<c041f348>] (gpiochip_find) from [<c04236ac>]
>>> (of_get_named_gpiod_flags+0x70/0x8c)
>>> [    4.360504] [<c04236ac>] (of_get_named_gpiod_flags) from
>>> [<c0422958>] (gpiod_get_index+0x80/0x22c)
>>> [    4.369873] [<c0422958>] (gpiod_get_index) from [<c0422bd0>]
>>> (gpiod_get_array+0x60/0xa8)
>>> [    4.378326] [<c0422bd0>] (gpiod_get_array) from [<c041ecac>]
>>> (devm_gpiod_get_array+0x3c/0x7c)
>>> [    4.387237] [<c041ecac>] (devm_gpiod_get_array) from [<c0593324>]
>>> (mmc_pwrseq_simple_probe+0x54/0xa8)
>>> [    4.396881] [<c0593324>] (mmc_pwrseq_simple_probe) from
> 
> Why is mmc_pwrseq_simple_probe being called? I don't see compatible
> "mmc-pwrseq-simple" in omap3-gta04.dtsi.
> 
> Or am I looking at the wrong DT file?
> 
> 
>>> [<c0481c08>] (platform_drv_probe+0x50/0xa0)
>>> [    4.406372] [<c0481c08>] (platform_drv_probe) from [<c047fce8>]
>>> (driver_probe_device+0x134/0x29c)
>>> [    4.415649] [<c047fce8>] (driver_probe_device) from [<c047fed8>]
>>> (__driver_attach+0x88/0xac)
>>> [    4.424468] [<c047fed8>] (__driver_attach) from [<c047e3b8>]
>>> (bus_for_each_dev+0x6c/0x90)
>>> [    4.433013] [<c047e3b8>] (bus_for_each_dev) from [<c047f398>]
>>> (bus_add_driver+0xcc/0x1e8)
>>> [    4.441589] [<c047f398>] (bus_add_driver) from [<c0480e28>]
>>> (driver_register+0xac/0xf4)
>>> [    4.449951] [<c0480e28>] (driver_register) from [<c010192c>]
>>> (do_one_initcall+0xac/0x154)
>>> [    4.458526] [<c010192c>] (do_one_initcall) from [<c0a00d78>]
>>> (kernel_init_freeable+0x120/0x1ec)
>>> [    4.467620] [<c0a00d78>] (kernel_init_freeable) from [<c06ced18>]
>>> (kernel_init+0x8/0x110)
>>> [    4.476196] [<c06ced18>] (kernel_init) from [<c01070d0>]
>>> (ret_from_fork+0x14/0x24)
>>> [    4.484100] Code: e5940000 e8bd4010 eaf892e1 e92d4038 (e590c06c)
>>> [    4.490539] ---[ end trace ad1af1376ad53c79 ]---
>>> [    4.495361] note: swapper/0[1] exited with preempt_count 1
>>> [    4.503417] Kernel panic - not syncing: Attempted to kill init!
>>> exitcode=0x0000000b
>>>
>>> during trying to lookup for gpio in pwrseq_simple node.
>>>
>>> I did some investigation and some lines above I can see:
>>>
>>> [    0.820983] omap-gpmc 6e000000.gpmc: GPMC revision 5.0
>>> [    0.821319] gpmc_mem_init: disabling cs 0 mapped at 0x0-0x1000000
>>> [    0.821411] gpiochip_find_base: found new base at 508
>>> [    0.821441] gpio gpiochip6: gpiodev_add_to_list adding: omap-gpmc
>>> [    0.821502] gpio gpiochip6: (omap-gpmc): added GPIO chardev (254:6)
>>> [    0.825042] gpiochip_setup_dev: registered GPIOs 508 to 511 on
>>> device: gpiochip6 (omap-gpmc)
>>> [    0.825286] omap-gpmc 6e000000.gpmc: cannot request GPMC CS 0
>>> [    0.825317] omap-gpmc 6e000000.gpmc: failed to probe DT children
>>> [    0.829620] omap-gpmc: probe of 6e000000.gpmc failed with error -16
>>>
>>> negative return code comes from: allocated_resource (in gpmc_cs_request)
>>>
>>> I add some debug functions to gpiolib and it turns out that omap-gpmc
>>> gpio's are added to list of gpio chips but because probe of gpmc
>>> failed then pointer to dt node is null and then it fails in
>>> of_gpiochip_find_and_xlate with null pointer access. Any idea what can
>>> cause this or do you have other report that booting doesn't work? Many
>>> thanks.
>>
>> Roger, any ideas about this one?
> 
> OK. Looks like we're missing a clean up of the gpio_chip when
> gpmc_probe_dt_children() fails. I'll send out a patch for that and this should
> fix the NULL pointer issue.

Actually, we are calling gpmc_gpio_exit() if gpmc_probe_dt_children() fails.
and in gpmc_gpio_exit() we do a gpiochip_remove().

So I don't see why mmc-pwrseq-simple gpio failing is related to GPMC.

> 
> However, we still need to figure out why gpmc_cs_request() is failing.
> Thanks for pointing out that allocated_resource() fails, but any idea why
> that might happen?
> 
> The ranges property for CS0 seems to be sane for omap3-gta04.dtsi.
> 
> Have you made any local changes to that dtsi?

This question still applies.


cheers,
-roger