[SRU] [B/C/D] [PATCH 0/8] Sync AMD MP2 I2C driver with upstream version

[Kai-Heng Feng]

at 17:41, Stefan Bader <stefan.bader at canonical.com> wrote:

> On 24.04.19 11:05, Kai-Heng Feng wrote:
>> at 14:23, Khaled Elmously <khalid.elmously at canonical.com> wrote:
>>
>>> On 2019-04-17 22:55:42 , Kai-Heng Feng wrote:
>>>> at 22:33, Stefan Bader <stefan.bader at canonical.com> wrote:
>>>>
>>>>> On 02.04.19 05:38, Kai-Heng Feng wrote:
>>>>>> BugLink: https://bugs.launchpad.net/bugs/1787775
>>>>>>
>>>>>> [Impact]
>>>>>> AMD MP2 I2C driver doesn't support more than one bus.
>>>>>> This makes touchpad on Lenovo Yoga 530 doensn't work as expected.
>>>>>>
>>>>>> [Fix]
>>>>>> Sync the MP2 driver with upstream version.
>>>>>>
>>>>>> [Test]
>>>>>> The new upstream driver doesn't break on Latitude 5495.
>>>>>> Users haven't given any feedback yet, but since Disco is freezing I
>>>>>> am sending this out.
>>>>>>
>>>>>> [Regression Potential]
>>>>>> Low. It's from upstream, and only a subset of Raven Ridge has this
>>>>>> device.
>>>>>>
>>>>>> Elie Morisse (1):
>>>>>>   i2c: Add drivers for the AMD PCIe MP2 I2C controller
>>>>>>
>>>>>> Kai-Heng Feng (4):
>>>>>>   Revert "UBUNTU: SAUCE: i2c:amd Depends on ACPI"
>>>>>>   Revert "UBUNTU: SAUCE: i2c:amd move out pointer in union
>>>>>>     i2c_event_base"
>>>>>>   Revert "UBUNTU: SAUCE: i2c:amd I2C Driver based on PCI Interface for
>>>>>>     upcoming platform"
>>>>>>   UBUNTU: [Config] Update config for AMD MP2 I2C driver
>>>>>>
>>>>>> Wolfram Sang (3):
>>>>>>   i2c: add helpers to ease DMA handling
>>>>>>   i2c: add a message flag for DMA safe buffers
>>>>>>   i2c: add extra check to safe DMA buffer helper
>>>>>>
>>>>>>  Documentation/i2c/busses/i2c-amd-mp2          |  23 +
>>>>>>  MAINTAINERS                                   |   8 +
>>>>>>  .../config/amd64/config.common.amd64          |   2 +-
>>>>>>  debian.master/config/i386/config.common.i386  |   2 +-
>>>>>>  drivers/i2c/busses/Kconfig                    |  12 +-
>>>>>>  drivers/i2c/busses/Makefile                   |   3 +-
>>>>>>  drivers/i2c/busses/i2c-amd-mp2-pci.c          | 483 ++++++++++++++
>>>>>>  drivers/i2c/busses/i2c-amd-mp2-plat.c         | 367 ++++++++++
>>>>>>  drivers/i2c/busses/i2c-amd-mp2.h              | 219 ++++++
>>>>>>  drivers/i2c/busses/i2c-amd-pci-mp2.c          | 625 ------------------
>>>>>>  drivers/i2c/busses/i2c-amd-pci-mp2.h          | 253 -------
>>>>>>  drivers/i2c/busses/i2c-amd-platdrv.c          | 335 ----------
>>>>>>  drivers/i2c/i2c-core-base.c                   |  51 ++
>>>>>>  include/linux/i2c.h                           |   3 +
>>>>>>  include/uapi/linux/i2c.h                      |   3 +
>>>>>>  15 files changed, 1166 insertions(+), 1223 deletions(-)
>>>>>>  create mode 100644 Documentation/i2c/busses/i2c-amd-mp2
>>>>>>  create mode 100644 drivers/i2c/busses/i2c-amd-mp2-pci.c
>>>>>>  create mode 100644 drivers/i2c/busses/i2c-amd-mp2-plat.c
>>>>>>  create mode 100644 drivers/i2c/busses/i2c-amd-mp2.h
>>>>>>  delete mode 100644 drivers/i2c/busses/i2c-amd-pci-mp2.c
>>>>>>  delete mode 100644 drivers/i2c/busses/i2c-amd-pci-mp2.h
>>>>>>  delete mode 100644 drivers/i2c/busses/i2c-amd-platdrv.c
>>>>> I am a bit hesitant to do this especially in Bionic. Have you done any
>>>>> wider
>>>>> regression testing with other hardware which uses this driver? That one
>>>>> Dell
>>>>> might be better off but that would not necessarily guarantee that
>>>>> nothing else
>>>>> does regress.
>>>>
>>>> No we’ve only enabled one system with AMD MP2. So it’s the only system  
>>>> I can
>>>> test.
>>>>
>>>> So there’s no guarantee. What I can confirm is that it used to only  
>>>> work on
>>>> the Dell system, now it works on both the Dell one and Lenovo Yoga.
>>>>
>>>>> Also the config changes silently change things from being built-in for
>>>>> 32bit and
>>>>> 64bit kernels to only being available as a module for 64bit kernels.
>>>>> That would
>>>>> mean any user who was running 32bit will loose that driver support. And
>>>>> you can
>>>>> be sure that if there is any possibility of doing that, there will be
>>>>> some user
>>>>> who did.
>>>>
>>>> Ryzen based systems only support 64bits [1]:
>>>> *OS Support
>>>> Windows 10 - 64-Bit Edition
>>>> RHEL x86 64-Bit
>>>> Ubuntu x86 64-Bit
>>>>
>>>> [1] https://www.amd.com/en/products/apu/amd-ryzen-5-2500u
>>>
>>> I had thought the AMD64 specification explicitly supports i386 as "legacy
>>> mode", as per page 2 of [2]
>>
>> CPU-wise yes. But the chipset and other components comes with Ryzen
>>
>> I just tried to boot a live 16.04.6 image on a Ryzen system, and it  
>> hangs at
>> certain point.
>>
>>> Is there a reason the MP2 driver can no longer be built for 32-bit?
>>
>> Of course it can be built agains 32-bit, but Ryzen as a whole doesn’t  
>> really
>> support 32-bit OS.
>
> This is a problem for a stable update. We have released with the driver  
> built-in
> for both amd64 and i386. So we cannot take away that support with any  
> stable
> update. Even if in theory nothing can use it.

Ok. it’s reasonable to keep it enabled in 3816. Do we need to change it  
back as builtin?

Kai-Heng

>
> -Stefan
>
>> Kai-Heng
>>
>>> [2] https://www.amd.com/system/files/TechDocs/24592.pdf
>>>
>>>
>>>
>>>> Kai-Heng
>>>>
>>>>> -Stefan
>>>>
>>>>
>>>>
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