[Pixman] [PATCH pixman] V7 implement PIXMAN_FILTER_GOOD/BEST

Oded Gabbay oded.gabbay at gmail.com
Mon Jan 4 00:38:16 PST 2016

Hi Bill,
Thanks for v7.
For future reference, when you resend a patch or a patch series, I
recommend that you follow the following guidelines (taken from the
Linux kernel community):

1. When creating the patches with git format-patch, add the following
flag: "--subject-prefix="PATCH vX". That way, the title of each patch
will contain the version information so it can be easily recognized to
which version it belongs.

2. Highlighting the major changes in the cover letter is very good.
However, you are supposed to write *every* change (maybe except
trivial spelling issues) in each of the patches commit messages, so
the person(s) reviewing your revised patches will know exactly what
was changed in each patch, instead of trying to guess from the cover
letter which patch has changed and which not. If the patch hasn't
changed at all, you can omit this part.

e.g. a sample commit message (six versions):

amdkfd: Add amdkfd skeleton driver

This patch adds the amdkfd skeleton driver. The driver does nothing except
define a /dev/kfd device.

It returns -ENODEV on all amdkfd IOCTLs.


- Move bool field to the end of structure
- Removed the pmc ioctls
- Added a meaningful error message for ioctl error.


- Create a new folder drm/amd and move amdkfd from drm/radeon/ to drm/amd/
- Remove scheduler_class from kfd_priv.h as it was never used
- Add skeleton implementation of the Get Version IOCTL


- Update module version to the correct number
- Remove the "default m" from the Kconfig file

Signed-off-by: Oded Gabbay <oded.gabbay at amd.com>


If you want/have the time to resend v7 with the guidelines I wrote, it
would be highly appreciated, but its not mandatory.



On Mon, Jan 4, 2016 at 5:12 AM,  <spitzak at gmail.com> wrote:
> Differences from previous version:
> - Added compile-time option to pipe filters to gnuplot for analysis.
> - Fixed integral when one of the filters is IMPULSE, previous version was
> offsetting the sample from the center.
> - Distribute fixed-point error on all samples, rather than putting it all
> on the center.
> - If reconstruct=impulse and scale < 1 (or sample=impulse) then it was
> producing garbage by attempting to renormalize filters that should not
> sum to 1. Even the "correct" result is useless, so I just made this set
> the scale to 1.
> - Comments and formatting fixes.
> I consider all patches except the last one to be bug fixes. The last
> patch changes the output for GOOD or BEST filter settings. Output is
> nearly identical towhat Cairo is producing now, but has some minor
> tweaks to cutoffs between filters and handling of very small scales.
> This also detects more cases where nearest or bilinear can be used as
> a fast path.
> With all of these applied, the filter generation can be removed from cairo as
> pixman will do it. The fallback to image for the X11 backend could be removed
> if it is known the X11 server is using this new version.
> This is also a necessary step in order to introduce 2-pass image filtering
> to pixman. Currently software such as Cairo cannot use the filtering in
> pixman and this means it will bypass any such improvements.
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