Subject: Re: Making a common API for cpu frequency drivers
To: Juan RP <juan@xtrarom.org>
From: Jachym Holecek <freza@dspfpga.com>
List: tech-kern
Date: 09/04/2006 00:38:50
Hello,
[Err, forgot to group-reply previously...]
# Juan RP 2006-09-03:
> I have the following code:
>
> http://www.xtrarom.org/~juan/sysmon_cpufreq/cpufreq.diff <- kernel part
> http://www.xtrarom.org/~juan/sysmon_cpufreq/dict_kern.c <- userland
Shouldn't SMCPUFREQ_GDICT be _IOWR? You want to copy plistref into
the kernel to get valid size & userland pointer so that you know
where to copyout() the externalized dict. For this, _IOW is enough
but it seems you also need the R bit (see common/lib/libprop/prop_kern.c)
to read back real size of externalized form.
-- Jachym