Re: [PATCH v2 00/10] Refine the locking for dev->iommu_group

Marek Szyprowski
2023-08-08T13:08:46Z

Hi Jason,

On 08.08.2023 15:00, Jason Gunthorpe wrote:
> On Tue, Aug 08, 2023 at 02:32:48PM +0200, Marek Szyprowski wrote:
>> On 08.08.2023 12:31, Chen-Yu Tsai wrote:
>>> On Mon, Aug 7, 2023 at 8:54 PM Joerg Roedel <joro@8bytes.org> wrote:
>>>> On Mon, Jul 31, 2023 at 02:50:23PM -0300, Jason Gunthorpe wrote:
>>>>> Jason Gunthorpe (10):
>>>>> iommu: Remove useless group refcounting
>>>>> iommu: Add a lockdep assertion for remaining dev->iommu_group reads
>>>>> iommu: Add generic_single_device_group()
>>>>> iommu/sun50i: Convert to generic_single_device_group()
>>>>> iommu/sprd: Convert to generic_single_device_group()
>>>>> iommu/rockchip: Convert to generic_single_device_group()
>>>>> iommu/ipmmu-vmsa: Convert to generic_single_device_group()
>>>>> iommu/omap: Convert to generic_single_device_group()
>>>>> iommu: Complete the locking for dev->iommu_group
>>>>> iommu/intel: Fix missing locking for show_device_domain_translation()
>>>>>
>>>>> drivers/iommu/intel/debugfs.c | 34 ++++----
>>>>> drivers/iommu/iommu.c | 155 +++++++++++++++++++++------------
>>>>> drivers/iommu/ipmmu-vmsa.c | 22 ++---
>>>>> drivers/iommu/omap-iommu.c | 30 +------
>>>>> drivers/iommu/omap-iommu.h | 2 +-
>>>>> drivers/iommu/rockchip-iommu.c | 22 +----
>>>>> drivers/iommu/sprd-iommu.c | 24 +----
>>>>> drivers/iommu/sun50i-iommu.c | 29 ++----
>>>>> include/linux/iommu.h | 3 +
>>>>> 9 files changed, 138 insertions(+), 183 deletions(-)
>>>> Applied, thanks for the nice cleanup!
>>> This series seems to cause a hung task during boot on MediaTek platforms.
>>> It hangs with next-20230808. Reverting the 10 commits from this series
>>> makes the system boot up again.
>> I confirm that next-20230808 is broken on ARM 32bit based Exynos boards
>> too. Boards lock up very early during boot. I will try to investigate
>> this soon.
> Any of the drivers that use platform device as the iommu_device will
> have a problem, please try:
>
> https://lore.kernel.org/linux-iommu/ZNIz%2FNVLb6WqqvQx@nvidia.com/

I've checked and it doesn't help in my case. I will soon check why.

Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland