2022-09-16 13:27:28

by Jan Dąbroś

Subject: [PATCH -next 0/2] Add i2c arbitration support for new SoCs

This patchset comprises changes into i2c-designware-amdpsp.c module
which aims to add support for new SoCs, while keep backward
compatibility with Cezanne platforms.

Beside new algorithm introduced for the PSP-x86 communication, it also
switches from MSR/MMIO access to SMN (System Management Network) since
only the latter is working on both old new revisions of SoCs.

Jan Dabros (2):
i2c: designware: Switch from using MMIO access to SMN access
i2c: designware: Add support for new SoCs in AMDPSP driver

arch/x86/include/asm/amd_nb.h | 1 +
arch/x86/kernel/amd_nb.c | 3 +-
drivers/i2c/busses/i2c-designware-amdpsp.c | 199 +++++++++++++-------
drivers/i2c/busses/i2c-designware-core.h | 1 -
drivers/i2c/busses/i2c-designware-platdrv.c | 1 -
5 files changed, 134 insertions(+), 71 deletions(-)

--
2.37.3.968.ga6b4b080e4-goog

2022-09-19 14:22:01

by Andy Shevchenko

Subject: Re: [PATCH -next 0/2] Add i2c arbitration support for new SoCs

On Fri, Sep 16, 2022 at 03:18:52PM +0200, Jan Dabros wrote:
> This patchset comprises changes into i2c-designware-amdpsp.c module
> which aims to add support for new SoCs, while keep backward
> compatibility with Cezanne platforms.
>
> Beside new algorithm introduced for the PSP-x86 communication, it also
> switches from MSR/MMIO access to SMN (System Management Network) since
> only the latter is working on both old new revisions of SoCs.

Which one is better performance/energy/etc wise? If it's not the SMN,
can we keep better in place?

--
With Best Regards,
Andy Shevchenko