On 22-Apr-21 10:29 AM, Richael Zhuang wrote:
-----Original Message-----
From: Burakov, Anatoly <[email protected]>
Sent: Thursday, April 22, 2021 5:06 PM
To: Richael Zhuang <[email protected]>; [email protected]
Cc: nd <[email protected]>; David Hunt <[email protected]>
Subject: Re: [dpdk-dev] [PATCH v1 1/1] power: add support for cppc cpufreq
On 22-Apr-21 7:15 AM, Richael Zhuang wrote:
Currently in DPDK only acpi_cpufreq and pstate_cpufreq drivers are
supported, which are both not available on arm64 platforms. Add
support for cppc_cpufreq driver which works on most arm64 platforms.
Signed-off-by: Richael Zhuang <[email protected]>
---
Just a general note: this looks like a copy-paste of pstate code. Which is
perfectly fine, except that we can do better than copying some faults of the
pstate code to other drivers. I've submitted a patch [1] attempting to fix
some of the pressing issues and code duplication in pstate driver, but i'm
sure with a fresh driver, you can do even better :)
[1]
http://patches.dpdk.org/project/dpdk/patch/20210402092701.258316-1-
[email protected]/
--
Thanks,
Anatoly
For CPPC is defined in acpi v5.0+ spec, I reused most code in acpi_cpufreq to
get a quick workable version on our platform with only cppc driver. I have
verified its basic functions. If you find some problems please help to point
out thus I can rework it. Thanks .
Best Regards,
Richael
Well, pstate code was copied from ACPI so it does share the same flaws:
- Lots of code duplication (e.g. snprintf for filename, fopen sequences,
etc.)
- Confusing and bug-prone error handling (e.g. return macros in the
middle of a function)
- Mixing power management logic and gory details of string handling
Good examples of the above are in your `power_check_turbo()` function -
lots of string handling code interspersed with file opens, and actual
logic of power management.
Please see the patch i linked earlier [1] to understand what kind of
changes i'm suggesting. Perhaps you could do even better :)
[1]
http://patches.dpdk.org/project/dpdk/patch/[email protected]/
--
Thanks,
Anatoly
