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Subject: Re: next/master bisection: baseline.login on r8a77960-ulcb
To:     Thierry Reding <thierry.reding@gmail.com>,
        Heiko Thiery <heiko.thiery@gmail.com>
Cc:     Guillaume Tucker <guillaume.tucker@collabora.com>,
        Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
        Jianxiong Gao <jxgao@google.com>,
        Christoph Hellwig <hch@lst.de>,
        "kernelci-results@groups.io" <kernelci-results@groups.io>,
        linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org,
        Marek Szyprowski <m.szyprowski@samsung.com>
References: <60346234.1c69fb81.cd55e.770d@mx.google.com>
 <7ac4a45f-b95e-acc0-f5bc-e4f870ac0bf1@collabora.com>
 <db197ccf-3b55-098e-bc19-ca8adc98c6b2@gmail.com>
 <YDeFbC8DzsB1GYNY@ulmo.localdomain>
From:   Robin Murphy <robin.murphy@arm.com>
Message-ID: <6804ffd9-4558-abd4-db17-22eb5617d996@arm.com>
Date:   Thu, 25 Feb 2021 11:14:57 +0000
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On 2021-02-25 11:09, Thierry Reding wrote:
> On Wed, Feb 24, 2021 at 10:39:42PM +0100, Heiko Thiery wrote:
>> Hi Christoph and all,
>>
>> On 23.02.21 10:56, Guillaume Tucker wrote:
>>> Hi Christoph,
>>>
>>> Please see the bisection report below about a boot failure on
>>> r8a77960-ulcb on next-20210222.
>>>
>>> Reports aren't automatically sent to the public while we're
>>> trialing new bisection features on kernelci.org but this one
>>> looks valid.
>>>
>>> The log shows a kernel panic, more details can be found here:
>>>
>>>     https://kernelci.org/test/case/id/6034bde034504edc9faddd2c/
>>>
>>> Please let us know if you need any help to debug the issue or try
>>> a fix on this platform.
>>
>> I am also seeing this problem on an iMX8MQ board and can help test if you
>> have a fix.
> 
> This is also causing boot failures on Jetson AGX Xavier. The origin is
> slightly different from the above kernelci.org report, but the BUG_ON is
> the same:
> 
>      [    2.650447] ------------[ cut here ]------------
>      [    2.650588] kernel BUG at include/linux/iommu-helper.h:23!
>      [    2.650729] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
>      [    2.654330] Modules linked in:
>      [    2.657474] CPU: 2 PID: 67 Comm: kworker/2:1 Not tainted 5.11.0-next-20210225-00025-gfd15609b3a81-dirty #120
>      [    2.667367] Hardware name: NVIDIA Jetson AGX Xavier Developer Kit (DT)
>      [    2.674096] Workqueue: events deferred_probe_work_func
>      [    2.679169] pstate: 40400089 (nZcv daIf +PAN -UAO -TCO BTYPE=--)
>      [    2.684949] pc : find_slots.isra.0+0x118/0x2f0
>      [    2.689494] lr : find_slots.isra.0+0x88/0x2f0
>      [    2.693696] sp : ffff800011faf950
>      [    2.697281] x29: ffff800011faf950 x28: 0000000000000001
>      [    2.702537] x27: 0000000000000001 x26: 0000000000000000
>      [    2.708131] x25: 0000000000000001 x24: 0000000105f03148
>      [    2.713556] x23: 0000000000000001 x22: ffff800011559000
>      [    2.718835] x21: ffff800011559a80 x20: 00000000edc00000
>      [    2.724493] x19: 0000000000000000 x18: 0000000000000020
>      [    2.729770] x17: ffff0003ffd7d160 x16: 0000000000000068
>      [    2.735173] x15: ffff000080b43150 x14: ffffffffffffffff
>      [    2.740944] x13: ffff000082b5d791 x12: 0000000000000040
>      [    2.746113] x11: ffff0000a0000248 x10: 0000000000000000
>      [    2.751882] x9 : 0000000000000000 x8 : ffff0003fed30000
>      [    2.757139] x7 : 0000000000000000 x6 : 0000000000000000
>      [    2.762818] x5 : 0000000000000000 x4 : 0000000000000000
>      [    2.767984] x3 : 00000001e8303148 x2 : 0000000000008000
>      [    2.773580] x1 : ffffffffffffffff x0 : 00000000001db800
>      [    2.778662] Call trace:
>      [    2.781136]  find_slots.isra.0+0x118/0x2f0
>      [    2.785137]  swiotlb_tbl_map_single+0x80/0x1b4
>      [    2.789858]  swiotlb_map+0x58/0x200
>      [    2.793355]  dma_direct_map_page+0x148/0x1c0
>      [    2.797386]  dma_map_page_attrs+0x2c/0x54
>      [    2.801411]  dw_pcie_host_init+0x40c/0x4c0
>      [    2.805633]  tegra_pcie_config_rp+0x7c/0x1f4
>      [    2.810155]  tegra_pcie_dw_probe+0x3d0/0x60c
>      [    2.814185]  platform_probe+0x68/0xe0
>      [    2.817688]  really_probe+0xe4/0x4c0
>      [    2.821362]  driver_probe_device+0x58/0xc0
>      [    2.825386]  __device_attach_driver+0xa8/0x104
>      [    2.829953]  bus_for_each_drv+0x78/0xd0
>      [    2.833434]  __device_attach+0xdc/0x17c
>      [    2.837631]  device_initial_probe+0x14/0x20
>      [    2.841680]  bus_probe_device+0x9c/0xa4
>      [    2.845160]  deferred_probe_work_func+0x74/0xb0
>      [    2.849734]  process_one_work+0x1cc/0x350
>      [    2.853822]  worker_thread+0x20c/0x3ac
>      [    2.858018]  kthread+0x128/0x134
>      [    2.860997]  ret_from_fork+0x10/0x34
>      [    2.864508] Code: ca180063 ea06007f 54fffee1 b50001e7 (d4210000)
>      [    2.870547] ---[ end trace e5c50bdcf12b316e ]---
>      [    2.875087] note: kworker/2:1[67] exited with preempt_count 2
>      [    2.880836] ------------[ cut here ]------------
> 
> I've confirmed that reverting the following commits makes the system
> boot again:
> 
>      47cfc5be1934 ("swiotlb: Validate bounce size in the sync/unmap path")
>      c6f50c7719e7 ("swiotlb: respect min_align_mask")
>      e952d9a1bc20 ("swiotlb: don't modify orig_addr in swiotlb_tbl_sync_single")
>      567d877f9a7d ("swiotlb: refactor swiotlb_tbl_map_single")
> 
> Let me know if I can help test any fixes for this.

FWIW, this sounds like it's probably the same thing for which a fix 
should be pending:

https://lore.kernel.org/linux-iommu/20210223072514.GA18079@lst.de/T/#u

Robin.