Re: [PATCH 5/8] clk: qcom: support for duplicate freq in RCG2 freq table

[Ziyang Huang]

在 2024/1/22 0:57, Andrew Lunn 写道:
> On Sun, Jan 21, 2024 at 08:42:34PM +0800, Ziyang Huang wrote:
> > From: Praveenkumar I <ipkumar@xxxxxxxxxxxxxx>
> >
> > Currently RCG code looks up the frequency table during set
> > rate and return the first available frequency greater than
> > requested rate. If CLK_SET_RATE_PARENT flag is set then the
> > set_rate request will go to its parent otherwise the clock
> > framework will configure pre-div, m and n according to the
> > returned frequency table entry. In this case, it is assuming
> > that parent clock will run in the same frequency with which
> > pre-div, m and n has been derived. But it may be possible
> > that the parent clock supports multiple frequency and the
> > same frequency can be derived with different pre-div, m and
> > n values depending upon current frequency.  Also, the same
> > frequency can be derived from different parent sources and
> > currently there is no option for having duplicate
> > frequencies in frequency table and choosing the best one
> > according to current rate.
> >
> > Now this patch adds the support for having duplicate
> > frequencies in frequency table. During set rate, it will
> > compare the actual rate for each entry with requested rate
> > and will select the best entry in which the difference will
> > be less.
> >
> > The existing functionality won’t be affected with this code
> > change since this code change will hit only if frequency
> > table has duplicate values.
>
> A good commit message for a change!
>
> > Change-Id: I97d9e1b55d8f3ee095f6f01729af527ba90e50e5
> > Signed-off-by: Abhishek Sahu <absahu@xxxxxxxxxxxxxx>
> > (cherry picked from commit 775e7d3b69ffc97afb5bd5a6c9c423f2f4d8a0b2)
> > Signed-off-by: Praveenkumar I <ipkumar@xxxxxxxxxxxxxx>
> >
> > Change-Id: If10193fc79a3c1375ab73597813745ff1f4df0ad
> >
> > Pick from https://git.codelinaro.org/clo/qsdk/oss/kernel/linux-ipq-5.4/-/commit/6dfb368bae130bee58e00ddf8330b55066e1c8c5
> >
> > Signed-off-by: Ziyang Huang <hzyitc@xxxxxxxxxxx>
>
> Please clean up these tags. These Change-ID tags are meaningless in
> mainline. 775e7d3b69ffc97afb5bd5a6c9c423f2f4d8a0b2 is not in mainline
> either. The picked from might be interesting, but please put it into
> the body of the commit message, not mixed in with the tags.
>
> Who actually wrote this patch? The first Signed-off-by: is from
> Abhishek Sahu. But you have a From of Praveenkumar I ?

I have no idea about this. This patch is from Qualcomm vendor linux 
code. And it's necessary for choosing parent and calculating clock rate 
correctly.

What's more, I don't known how to deal with these commit message since 
I'm not the author and I'm not sure do I have right to edit them even 
though this is GPL code.

>      Andrew
>
> ---
> pw-bot: cr