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

[Khaled Elmously]

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]

Is there a reason the MP2 driver can no longer be built for 32-bit?


[2] https://www.amd.com/system/files/TechDocs/24592.pdf



> Kai-Heng
> 
> > 
> > -Stefan
> 
> 
> 
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