From: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
To: Alexander Monakov <amonakov@ispras.ru>
Cc: linux-kernel@vger.kernel.org, Joerg Roedel <joro@8bytes.org>,
iommu@lists.linux-foundation.org
Subject: Re: [PATCH] iommu/amd: Fix event counter availability check
Date: Tue, 16 Jun 2020 16:35:48 +0700 [thread overview]
Message-ID: <b01994db-da9b-d8e6-e0c1-1af35dd62191@amd.com> (raw)
In-Reply-To: <alpine.LNX.2.20.13.2006152346320.21123@monopod.intra.ispras.ru>
On 6/16/20 3:48 AM, Alexander Monakov wrote:
>> Alexander
>>
>> On 6/1/20 4:01 PM, Alexander Monakov wrote:
>>> On Mon, 1 Jun 2020, Suravee Suthikulpanit wrote:
>>>
>>>>> Moving init_iommu_perf_ctr just after iommu_flush_all_caches resolves
>>>>> the issue. This is the earliest point in amd_iommu_init_pci where the
>>>>> call succeeds on my laptop.
>>>> According to your description, it should just need to be anywhere after
>>>> the
>>>> pci_enable_device() is called for the IOMMU device, isn't it? So, on your
>>>> system, what if we just move the init_iommu_perf_ctr() here:
>>> No, this doesn't work, as I already said in the paragraph you are responding
>>> to. See my last sentence in the quoted part.
>>>
>>> So the implication is init_device_table_dma together with subsequent cache
>>> flush is also setting up something that is necessary for counters to be
>>> writable.
>>>
>>> Alexander
>>>
>> Instead of blindly moving the code around to a spot that would just work,
>> I am trying to understand what might be required here. In this case,
>> the init_device_table_dma()should not be needed. I suspect it's the IOMMU
>> invalidate all command that's also needed here.
>>
>> I'm also checking with the HW and BIOS team. Meanwhile, could you please give
>> the following change a try:
> Hello. Can you give any update please?
>
> Alexander
>
Sorry for late reply. I have a reproducer and working with the HW team to understand the issue.
I should be able to provide update with solution by the end of this week.
Suravee
next prev parent reply other threads:[~2020-06-16 9:36 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-29 20:07 [PATCH] iommu/amd: Fix event counter availability check Alexander Monakov
2020-05-31 7:22 ` Alexander Monakov
2020-06-01 2:48 ` Paul Menzel
2021-02-21 13:44 ` Paul Menzel
2020-06-02 23:51 ` Shuah Khan
2020-06-03 6:54 ` Alexander Monakov
2021-02-26 21:44 ` Paul Menzel
2021-02-26 21:55 ` Shuah Khan
2020-06-01 7:37 ` Suravee Suthikulpanit
2020-06-01 9:01 ` Alexander Monakov
2020-06-01 15:10 ` Suravee Suthikulpanit
2020-06-01 16:09 ` Alexander Monakov
2020-06-15 20:48 ` Alexander Monakov
2020-06-16 9:35 ` Suravee Suthikulpanit [this message]
2020-06-30 19:22 ` Alexander Monakov
2020-09-17 17:55 ` Alexander Monakov
2021-02-21 13:49 ` Paul Menzel
2021-02-22 17:59 ` Suravee Suthikulpanit
2021-02-24 20:35 ` Paul Menzel
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