[PATCH v6 0/4] drivers/perf: add Synopsys DesignWare PCIe PMU driver support

[PATCH v6 0/4] drivers/perf: add Synopsys DesignWare PCIe PMU driver support

[Shuai Xue]

changes since v5:
- Rewrite the commit log to follow policy in pci_ids.h (Bjorn Helgaas)
- return error code when __dwc_pcie_pmu_probe failed (Baolin Wang)
- call 'cpuhp_remove_multi_state()' when exiting the driver. (Baolin Wang)
- pick up Review-by tag from Baolin for Patch 1 and 3

changes since v4:

1. addressing commens from Bjorn Helgaas:
- reorder the includes by alpha
- change all macros with upper-case hex
- change ras_des type into u16
- remove unnecessary outer "()"
- minor format changes

2. Address commensts from Jonathan Cameron:
- rewrite doc and add a example to show how to use lane event

3. fix compile error reported by: kernel test robot
- remove COMPILE_TEST and add depend on PCI in kconfig
- add Reported-by: kernel test robot <lkp@intel.com>

Changes since v3:

1. addressing comments from Robin Murphy:
- add a prepare patch to define pci id in linux/pci_ids.h
- remove unnecessary 64BIT dependency
- fix DWC_PCIE_PER_EVENT_OFF/ON macro
- remove dwc_pcie_pmu struct and move all its fileds into dwc_pcie_rp_info
- remove unnecessary format field show
- use sysfs_emit() instead of all the assorted sprintf() and snprintf() calls.
- remove unnecessary spaces and remove unnecessary cast to follow event show convention
- remove pcie_pmu_event_attr_is_visible
- fix a refcout leak on error branch when walk pci device in for_each_pci_dev
- remove bdf field from dwc_pcie_rp_info and calculate it at runtime
- finish all the checks before allocating rp_info to avoid hanging wasted memory
- remove some unused fields
- warp out control register configuration from sub function to .add()
- make function return type with a proper signature
- fix lane event count enable by clear DWC_PCIE_CNT_ENABLE field first
- pass rp_info directly to the read_*_counter helpers and in start, stop and add callbacks
- move event type validtion into .event_init()
- use is_sampling_event() to be consistent with everything else of pmu drivers
- remove unnecessary dev_err message in .event_init()
- return EINVAL instead EOPNOTSUPP for not a valid event 
- finish all the checks before start modifying the event
- fix sibling event check by comparing event->pmu with sibling->pmu
- probe PMU for each rootport independently
- use .update() as .read() directly
- remove dynamically generating symbolic name of lane event
- redefine static symbolic name of lane event and leave lane filed to user
- add CPU hotplug support

2. addressing comments from Baolin:
- add a mask to avoid possible overflow

Changes since v2 addressing comments from Baolin:
- remove redundant macro definitions
- use dev_err to print error message
- change pmu_is_register to boolean
- use PLATFORM_DEVID_NONE macro
- fix module author format

Changes since v1:

1. address comments from Jonathan:
- drop marco for PMU name and VSEC version
- simplify code with PCI standard marco
- simplify code with FIELD_PREP()/FIELD_GET() to replace shift marco
- name register filed with single _ instead double
- wrap dwc_pcie_pmu_{write}_dword out and drop meaningless snaity check 
- check vendor id while matching vesc with pci_find_vsec_capability()
- remove RP_NUM_MAX and use a list to organize PMU devices for rootports
- replace DWC_PCIE_CREATE_BDF with standard PCI_DEVID
- comments on riping register together

2. address comments from Bjorn:
- rename DWC_PCIE_VSEC_ID to DWC_PCIE_VSEC_RAS_DES_ID
- rename cap_pos to ras_des
- simplify declare of device_attribute with DEVICE_ATTR_RO
- simplify code with PCI standard macro and API like pcie_get_width_cap()
- fix some code style problem and typo
- drop meaningless snaity check of container_of

3. address comments from Yicong:
- use sysfs_emit() to replace sprintf()
- simplify iteration of pci device with for_each_pci_dev
- pick preferred CPUs on a near die and add comments
- unregister PMU drivers only for failed ones
- log on behalf PMU device and give more hint
- fix some code style problem

(Thanks for all comments and they are very valuable to me)

This patchset adds the PCIe Performance Monitoring Unit (PMU) driver support
for T-Head Yitian 710 SoC chip. Yitian 710 is based on the Synopsys PCI Express
Core controller IP which provides statistics feature.

Shuai Xue (4):
  docs: perf: Add description for Synopsys DesignWare PCIe PMU driver
  PCI: Add Alibaba Vendor ID to linux/pci_ids.h
  drivers/perf: add DesignWare PCIe PMU driver
  MAINTAINERS: add maintainers for DesignWare PCIe PMU driver

 .../admin-guide/perf/dwc_pcie_pmu.rst         |  97 +++
 Documentation/admin-guide/perf/index.rst      |   1 +
 MAINTAINERS                                   |   6 +
 drivers/infiniband/hw/erdma/erdma_hw.h        |   2 -
 drivers/perf/Kconfig                          |   7 +
 drivers/perf/Makefile                         |   1 +
 drivers/perf/dwc_pcie_pmu.c                   | 706 ++++++++++++++++++
 include/linux/pci_ids.h                       |   2 +
 8 files changed, 820 insertions(+), 2 deletions(-)
 create mode 100644 Documentation/admin-guide/perf/dwc_pcie_pmu.rst
 create mode 100644 drivers/perf/dwc_pcie_pmu.c

-- 
2.20.1.12.g72788fdb


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Re: [PATCH v6 0/4] drivers/perf: add Synopsys DesignWare PCIe PMU driver support

[Shuai Xue]

On 2023/6/6 15:49, Shuai Xue wrote:
> changes since v5:
> - Rewrite the commit log to follow policy in pci_ids.h (Bjorn Helgaas)
> - return error code when __dwc_pcie_pmu_probe failed (Baolin Wang)
> - call 'cpuhp_remove_multi_state()' when exiting the driver. (Baolin Wang)
> - pick up Review-by tag from Baolin for Patch 1 and 3
> 
> changes since v4:
> 
> 1. addressing commens from Bjorn Helgaas:
> - reorder the includes by alpha
> - change all macros with upper-case hex
> - change ras_des type into u16
> - remove unnecessary outer "()"
> - minor format changes
> 
> 2. Address commensts from Jonathan Cameron:
> - rewrite doc and add a example to show how to use lane event
> 
> 3. fix compile error reported by: kernel test robot
> - remove COMPILE_TEST and add depend on PCI in kconfig
> - add Reported-by: kernel test robot <lkp@intel.com>
> 
> Changes since v3:
> 
> 1. addressing comments from Robin Murphy:
> - add a prepare patch to define pci id in linux/pci_ids.h
> - remove unnecessary 64BIT dependency
> - fix DWC_PCIE_PER_EVENT_OFF/ON macro
> - remove dwc_pcie_pmu struct and move all its fileds into dwc_pcie_rp_info
> - remove unnecessary format field show
> - use sysfs_emit() instead of all the assorted sprintf() and snprintf() calls.
> - remove unnecessary spaces and remove unnecessary cast to follow event show convention
> - remove pcie_pmu_event_attr_is_visible
> - fix a refcout leak on error branch when walk pci device in for_each_pci_dev
> - remove bdf field from dwc_pcie_rp_info and calculate it at runtime
> - finish all the checks before allocating rp_info to avoid hanging wasted memory
> - remove some unused fields
> - warp out control register configuration from sub function to .add()
> - make function return type with a proper signature
> - fix lane event count enable by clear DWC_PCIE_CNT_ENABLE field first
> - pass rp_info directly to the read_*_counter helpers and in start, stop and add callbacks
> - move event type validtion into .event_init()
> - use is_sampling_event() to be consistent with everything else of pmu drivers
> - remove unnecessary dev_err message in .event_init()
> - return EINVAL instead EOPNOTSUPP for not a valid event 
> - finish all the checks before start modifying the event
> - fix sibling event check by comparing event->pmu with sibling->pmu
> - probe PMU for each rootport independently
> - use .update() as .read() directly
> - remove dynamically generating symbolic name of lane event
> - redefine static symbolic name of lane event and leave lane filed to user
> - add CPU hotplug support
> 
> 2. addressing comments from Baolin:
> - add a mask to avoid possible overflow
> 
> Changes since v2 addressing comments from Baolin:
> - remove redundant macro definitions
> - use dev_err to print error message
> - change pmu_is_register to boolean
> - use PLATFORM_DEVID_NONE macro
> - fix module author format
> 
> Changes since v1:
> 
> 1. address comments from Jonathan:
> - drop marco for PMU name and VSEC version
> - simplify code with PCI standard marco
> - simplify code with FIELD_PREP()/FIELD_GET() to replace shift marco
> - name register filed with single _ instead double
> - wrap dwc_pcie_pmu_{write}_dword out and drop meaningless snaity check 
> - check vendor id while matching vesc with pci_find_vsec_capability()
> - remove RP_NUM_MAX and use a list to organize PMU devices for rootports
> - replace DWC_PCIE_CREATE_BDF with standard PCI_DEVID
> - comments on riping register together
> 
> 2. address comments from Bjorn:
> - rename DWC_PCIE_VSEC_ID to DWC_PCIE_VSEC_RAS_DES_ID
> - rename cap_pos to ras_des
> - simplify declare of device_attribute with DEVICE_ATTR_RO
> - simplify code with PCI standard macro and API like pcie_get_width_cap()
> - fix some code style problem and typo
> - drop meaningless snaity check of container_of
> 
> 3. address comments from Yicong:
> - use sysfs_emit() to replace sprintf()
> - simplify iteration of pci device with for_each_pci_dev
> - pick preferred CPUs on a near die and add comments
> - unregister PMU drivers only for failed ones
> - log on behalf PMU device and give more hint
> - fix some code style problem
> 
> (Thanks for all comments and they are very valuable to me)
> 
> This patchset adds the PCIe Performance Monitoring Unit (PMU) driver support
> for T-Head Yitian 710 SoC chip. Yitian 710 is based on the Synopsys PCI Express
> Core controller IP which provides statistics feature.
> 
> Shuai Xue (4):
>   docs: perf: Add description for Synopsys DesignWare PCIe PMU driver
>   PCI: Add Alibaba Vendor ID to linux/pci_ids.h
>   drivers/perf: add DesignWare PCIe PMU driver
>   MAINTAINERS: add maintainers for DesignWare PCIe PMU driver
> 
>  .../admin-guide/perf/dwc_pcie_pmu.rst         |  97 +++
>  Documentation/admin-guide/perf/index.rst      |   1 +
>  MAINTAINERS                                   |   6 +
>  drivers/infiniband/hw/erdma/erdma_hw.h        |   2 -
>  drivers/perf/Kconfig                          |   7 +
>  drivers/perf/Makefile                         |   1 +
>  drivers/perf/dwc_pcie_pmu.c                   | 706 ++++++++++++++++++
>  include/linux/pci_ids.h                       |   2 +
>  8 files changed, 820 insertions(+), 2 deletions(-)
>  create mode 100644 Documentation/admin-guide/perf/dwc_pcie_pmu.rst
>  create mode 100644 drivers/perf/dwc_pcie_pmu.c
> 

Hi, all,

Gently ping. Any comments are welcomed.

Thank you.

Best Regards,
Shuai



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Re: [PATCH v6 0/4] drivers/perf: add Synopsys DesignWare PCIe PMU driver support

[Shuai Xue]

On 2023/6/16 16:39, Shuai Xue wrote:
> 
> 
> On 2023/6/6 15:49, Shuai Xue wrote:
>> changes since v5:
>> - Rewrite the commit log to follow policy in pci_ids.h (Bjorn Helgaas)
>> - return error code when __dwc_pcie_pmu_probe failed (Baolin Wang)
>> - call 'cpuhp_remove_multi_state()' when exiting the driver. (Baolin Wang)
>> - pick up Review-by tag from Baolin for Patch 1 and 3
>>
>> changes since v4:
>>
>> 1. addressing commens from Bjorn Helgaas:
>> - reorder the includes by alpha
>> - change all macros with upper-case hex
>> - change ras_des type into u16
>> - remove unnecessary outer "()"
>> - minor format changes
>>
>> 2. Address commensts from Jonathan Cameron:
>> - rewrite doc and add a example to show how to use lane event
>>
>> 3. fix compile error reported by: kernel test robot
>> - remove COMPILE_TEST and add depend on PCI in kconfig
>> - add Reported-by: kernel test robot <lkp@intel.com>
>>
>> Changes since v3:
>>
>> 1. addressing comments from Robin Murphy:
>> - add a prepare patch to define pci id in linux/pci_ids.h
>> - remove unnecessary 64BIT dependency
>> - fix DWC_PCIE_PER_EVENT_OFF/ON macro
>> - remove dwc_pcie_pmu struct and move all its fileds into dwc_pcie_rp_info
>> - remove unnecessary format field show
>> - use sysfs_emit() instead of all the assorted sprintf() and snprintf() calls.
>> - remove unnecessary spaces and remove unnecessary cast to follow event show convention
>> - remove pcie_pmu_event_attr_is_visible
>> - fix a refcout leak on error branch when walk pci device in for_each_pci_dev
>> - remove bdf field from dwc_pcie_rp_info and calculate it at runtime
>> - finish all the checks before allocating rp_info to avoid hanging wasted memory
>> - remove some unused fields
>> - warp out control register configuration from sub function to .add()
>> - make function return type with a proper signature
>> - fix lane event count enable by clear DWC_PCIE_CNT_ENABLE field first
>> - pass rp_info directly to the read_*_counter helpers and in start, stop and add callbacks
>> - move event type validtion into .event_init()
>> - use is_sampling_event() to be consistent with everything else of pmu drivers
>> - remove unnecessary dev_err message in .event_init()
>> - return EINVAL instead EOPNOTSUPP for not a valid event 
>> - finish all the checks before start modifying the event
>> - fix sibling event check by comparing event->pmu with sibling->pmu
>> - probe PMU for each rootport independently
>> - use .update() as .read() directly
>> - remove dynamically generating symbolic name of lane event
>> - redefine static symbolic name of lane event and leave lane filed to user
>> - add CPU hotplug support
>>
>> 2. addressing comments from Baolin:
>> - add a mask to avoid possible overflow
>>
>> Changes since v2 addressing comments from Baolin:
>> - remove redundant macro definitions
>> - use dev_err to print error message
>> - change pmu_is_register to boolean
>> - use PLATFORM_DEVID_NONE macro
>> - fix module author format
>>
>> Changes since v1:
>>
>> 1. address comments from Jonathan:
>> - drop marco for PMU name and VSEC version
>> - simplify code with PCI standard marco
>> - simplify code with FIELD_PREP()/FIELD_GET() to replace shift marco
>> - name register filed with single _ instead double
>> - wrap dwc_pcie_pmu_{write}_dword out and drop meaningless snaity check 
>> - check vendor id while matching vesc with pci_find_vsec_capability()
>> - remove RP_NUM_MAX and use a list to organize PMU devices for rootports
>> - replace DWC_PCIE_CREATE_BDF with standard PCI_DEVID
>> - comments on riping register together
>>
>> 2. address comments from Bjorn:
>> - rename DWC_PCIE_VSEC_ID to DWC_PCIE_VSEC_RAS_DES_ID
>> - rename cap_pos to ras_des
>> - simplify declare of device_attribute with DEVICE_ATTR_RO
>> - simplify code with PCI standard macro and API like pcie_get_width_cap()
>> - fix some code style problem and typo
>> - drop meaningless snaity check of container_of
>>
>> 3. address comments from Yicong:
>> - use sysfs_emit() to replace sprintf()
>> - simplify iteration of pci device with for_each_pci_dev
>> - pick preferred CPUs on a near die and add comments
>> - unregister PMU drivers only for failed ones
>> - log on behalf PMU device and give more hint
>> - fix some code style problem
>>
>> (Thanks for all comments and they are very valuable to me)
>>
>> This patchset adds the PCIe Performance Monitoring Unit (PMU) driver support
>> for T-Head Yitian 710 SoC chip. Yitian 710 is based on the Synopsys PCI Express
>> Core controller IP which provides statistics feature.
>>
>> Shuai Xue (4):
>>   docs: perf: Add description for Synopsys DesignWare PCIe PMU driver
>>   PCI: Add Alibaba Vendor ID to linux/pci_ids.h
>>   drivers/perf: add DesignWare PCIe PMU driver
>>   MAINTAINERS: add maintainers for DesignWare PCIe PMU driver
>>
>>  .../admin-guide/perf/dwc_pcie_pmu.rst         |  97 +++
>>  Documentation/admin-guide/perf/index.rst      |   1 +
>>  MAINTAINERS                                   |   6 +
>>  drivers/infiniband/hw/erdma/erdma_hw.h        |   2 -
>>  drivers/perf/Kconfig                          |   7 +
>>  drivers/perf/Makefile                         |   1 +
>>  drivers/perf/dwc_pcie_pmu.c                   | 706 ++++++++++++++++++
>>  include/linux/pci_ids.h                       |   2 +
>>  8 files changed, 820 insertions(+), 2 deletions(-)
>>  create mode 100644 Documentation/admin-guide/perf/dwc_pcie_pmu.rst
>>  create mode 100644 drivers/perf/dwc_pcie_pmu.c
>>
> 
> Hi, all,
> 
> Gently ping. Any comments are welcomed.


Hi, all,

Gentle ping.


> 
> Thank you.
>
> 
> Best Regards,
> Shuai
> 
> 

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Re: [PATCH v6 0/4] drivers/perf: add Synopsys DesignWare PCIe PMU driver support

[Shuai Xue]

On 2023/7/26 04:59, Bjorn Helgaas wrote:
> On Mon, Jul 24, 2023 at 10:18:07AM +0100, Jonathan Cameron wrote:
>> On Mon, 24 Jul 2023 10:34:08 +0800
>> Shuai Xue <xueshuai@linux.alibaba.com> wrote:
>>> On 2023/7/10 20:04, Shuai Xue wrote:
>>>> On 2023/6/16 16:39, Shuai Xue wrote:  
>>>>> On 2023/6/6 15:49, Shuai Xue wrote:  
> 
>>>>>> This patchset adds the PCIe Performance Monitoring Unit (PMU) driver support
>>>>>> for T-Head Yitian 710 SoC chip. Yitian 710 is based on the Synopsys PCI Express
>>>>>> Core controller IP which provides statistics feature.
> 
>> ...
>> Really a question for Bjorn I think, but here is my 2 cents...
>>
>> The problem here is that we need to do that fundamental redesign of the
>> way the PCI ports drivers work.  I'm not sure there is a path to merging
>> this until that is done.  The bigger problem is that I'm not sure anyone
>> is actively looking at that yet.  I'd like to look at this (as I have
>> the same problem for some other drivers), but it is behind various
>> other things on my todo list.
>>
>> Bjorn might be persuaded on a temporary solution, but that would come
>> with some maintenance problems, particularly when we try to do it
>> 'right' in the future.  Maybe adding another service driver would be
>> a stop gap as long as we know we won't keep doing so for ever. Not sure.
> 
> I think the question here is around the for_each_pci_dev() in
> __dwc_pcie_pmu_probe()?  I don't *like* that because of the
> assumptions it breaks (autoload doesn't work, hotplug doesn't work),
> but:
> 
>   - There are several other drivers that also do this,
>   - I don't have a better suggest for any of them,
>   - It's not a drivers/pci thing, so not really up to me anyway,
> 
> so I don't have any problem with this being merged as-is, as long as
> you can live with the limitations.
> 
> I don't think this series does anything to work around those
> limitations, i.e., it doesn't make up fake device IDs for module
> loading or fake events for hotplug, so it seems like we could improve
> the implementation later if we ever have a way to do it.
> 
> Bjorn

+ Will

Ok, thank you for confirmation, Bjorn. Then it comes to perf driver parts and
it is really a question for @Will I think.

What's your opinion about merging this patch set, @Will?

Best Regards,
Shuai


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Re: [PATCH v6 0/4] drivers/perf: add Synopsys DesignWare PCIe PMU driver support

[Will Deacon]

On Thu, Jul 27, 2023 at 11:45:22AM +0800, Shuai Xue wrote:
> 
> 
> On 2023/7/26 04:59, Bjorn Helgaas wrote:
> > On Mon, Jul 24, 2023 at 10:18:07AM +0100, Jonathan Cameron wrote:
> >> On Mon, 24 Jul 2023 10:34:08 +0800
> >> Shuai Xue <xueshuai@linux.alibaba.com> wrote:
> >>> On 2023/7/10 20:04, Shuai Xue wrote:
> >>>> On 2023/6/16 16:39, Shuai Xue wrote:  
> >>>>> On 2023/6/6 15:49, Shuai Xue wrote:  
> > 
> >>>>>> This patchset adds the PCIe Performance Monitoring Unit (PMU) driver support
> >>>>>> for T-Head Yitian 710 SoC chip. Yitian 710 is based on the Synopsys PCI Express
> >>>>>> Core controller IP which provides statistics feature.
> > 
> >> ...
> >> Really a question for Bjorn I think, but here is my 2 cents...
> >>
> >> The problem here is that we need to do that fundamental redesign of the
> >> way the PCI ports drivers work.  I'm not sure there is a path to merging
> >> this until that is done.  The bigger problem is that I'm not sure anyone
> >> is actively looking at that yet.  I'd like to look at this (as I have
> >> the same problem for some other drivers), but it is behind various
> >> other things on my todo list.
> >>
> >> Bjorn might be persuaded on a temporary solution, but that would come
> >> with some maintenance problems, particularly when we try to do it
> >> 'right' in the future.  Maybe adding another service driver would be
> >> a stop gap as long as we know we won't keep doing so for ever. Not sure.
> > 
> > I think the question here is around the for_each_pci_dev() in
> > __dwc_pcie_pmu_probe()?  I don't *like* that because of the
> > assumptions it breaks (autoload doesn't work, hotplug doesn't work),
> > but:
> > 
> >   - There are several other drivers that also do this,
> >   - I don't have a better suggest for any of them,
> >   - It's not a drivers/pci thing, so not really up to me anyway,
> > 
> > so I don't have any problem with this being merged as-is, as long as
> > you can live with the limitations.
> > 
> > I don't think this series does anything to work around those
> > limitations, i.e., it doesn't make up fake device IDs for module
> > loading or fake events for hotplug, so it seems like we could improve
> > the implementation later if we ever have a way to do it.
> > 
> > Bjorn
> 
> + Will
> 
> Ok, thank you for confirmation, Bjorn. Then it comes to perf driver parts and
> it is really a question for @Will I think.
> 
> What's your opinion about merging this patch set, @Will?

No fundamental objection from me, but I'll have a closer look when you
post a version addressing the feedback from Jonathan and Yicong.

Cheers,

Will

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Re: [PATCH v6 0/4] drivers/perf: add Synopsys DesignWare PCIe PMU driver support

[Shuai Xue]

On 2023/7/28 21:39, Will Deacon wrote:
> On Thu, Jul 27, 2023 at 11:45:22AM +0800, Shuai Xue wrote:
>>
>>
>> On 2023/7/26 04:59, Bjorn Helgaas wrote:
>>> On Mon, Jul 24, 2023 at 10:18:07AM +0100, Jonathan Cameron wrote:
>>>> On Mon, 24 Jul 2023 10:34:08 +0800
>>>> Shuai Xue <xueshuai@linux.alibaba.com> wrote:
>>>>> On 2023/7/10 20:04, Shuai Xue wrote:
>>>>>> On 2023/6/16 16:39, Shuai Xue wrote:  
>>>>>>> On 2023/6/6 15:49, Shuai Xue wrote:  
>>>
>>>>>>>> This patchset adds the PCIe Performance Monitoring Unit (PMU) driver support
>>>>>>>> for T-Head Yitian 710 SoC chip. Yitian 710 is based on the Synopsys PCI Express
>>>>>>>> Core controller IP which provides statistics feature.
>>>
>>>> ...
>>>> Really a question for Bjorn I think, but here is my 2 cents...
>>>>
>>>> The problem here is that we need to do that fundamental redesign of the
>>>> way the PCI ports drivers work.  I'm not sure there is a path to merging
>>>> this until that is done.  The bigger problem is that I'm not sure anyone
>>>> is actively looking at that yet.  I'd like to look at this (as I have
>>>> the same problem for some other drivers), but it is behind various
>>>> other things on my todo list.
>>>>
>>>> Bjorn might be persuaded on a temporary solution, but that would come
>>>> with some maintenance problems, particularly when we try to do it
>>>> 'right' in the future.  Maybe adding another service driver would be
>>>> a stop gap as long as we know we won't keep doing so for ever. Not sure.
>>>
>>> I think the question here is around the for_each_pci_dev() in
>>> __dwc_pcie_pmu_probe()?  I don't *like* that because of the
>>> assumptions it breaks (autoload doesn't work, hotplug doesn't work),
>>> but:
>>>
>>>   - There are several other drivers that also do this,
>>>   - I don't have a better suggest for any of them,
>>>   - It's not a drivers/pci thing, so not really up to me anyway,
>>>
>>> so I don't have any problem with this being merged as-is, as long as
>>> you can live with the limitations.
>>>
>>> I don't think this series does anything to work around those
>>> limitations, i.e., it doesn't make up fake device IDs for module
>>> loading or fake events for hotplug, so it seems like we could improve
>>> the implementation later if we ever have a way to do it.
>>>
>>> Bjorn
>>
>> + Will
>>
>> Ok, thank you for confirmation, Bjorn. Then it comes to perf driver parts and
>> it is really a question for @Will I think.
>>
>> What's your opinion about merging this patch set, @Will?
> 
> No fundamental objection from me, but I'll have a closer look when you
> post a version addressing the feedback from Jonathan and Yicong.

Thanks for your input! I appreciate that you don't have any fundamental objections
to merging the patch set. I'll definitely take into account the feedback from Jonathan
and Yicong before posting a revised version.


Best Regards,
Cheers.
Shuai

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