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

[Kai-Heng Feng]

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.

Kai-Heng

>
>
> [2] https://www.amd.com/system/files/TechDocs/24592.pdf
>
>
>
>> Kai-Heng
>>
>>> -Stefan
>>
>>
>>
>> -- 
>> kernel-team mailing list
>> kernel-team at lists.ubuntu.com
>> https://lists.ubuntu.com/mailman/listinfo/kernel-team