Re: [PATCH v4 12/12] staging: most: Documentation: update driver documentation

Re: [PATCH v4 12/12] staging: most: Documentation: update driver documentation

[Eugeniu Rosca]

Hello Christian, hello Andrey,
cc: Vladimir Barinov
cc: linux-renesas-soc

Our team currently has the requirement of adding MOST support to
the v4.14-based R-Car3 kernel [1], matching the level of features
and interfaces of mld-1.8.0 [2] release.

Based on a quick check [3], the mld-1.8.0 release contains 221 non-merge
non-mainline commits. It seems like at least some (most?) of them have
been reworked during upstreaming and are now part of vanilla, thanks to
your efforts.

Since you've actively participated in pushing the out-of-tree drivers
to mainline, could you please share your gut feeling whether the
current mainline state of the MOST subsystem matches the mld-1.8.0
release in terms of features and interfaces?

At first glance, such mld-1.8.0 functionalities like "flexible PCM
rate support" [4], as well as a number of dim2 sysfs entries [5-8]
appear to be missing in v5.1-rc5. Could you please feedback if these
have been deliberately dropped or didn't make their way for another
reason? What would be your recommendation between going the mld-1.8.0
and going the v5.1-rc5 way for MOST?

Best regards,
Eugeniu.

[1] https://git.kernel.org/pub/scm/linux/kernel/git/horms/renesas-bsp.git/
[2] https://github.com/microchip-ais/linux/releases/tag/mld-1.8.0
[3] git rev-list --no-merges --count  \
    $(git merge-base linux/master mld-1.8.0)..mld-1.8.0
    221
[4] https://github.com/microchip-ais/linux/commit/8821bad23ff2
    ("staging: most: aim-sound: add flexible PCM rate support")
[5] https://github.com/microchip-ais/linux/commit/5030f77717a1d7
    ("staging: most: dim2: add sysfs property dci/node_position")
[6] https://github.com/microchip-ais/linux/commit/3a840d7b504552
    ("staging: most: dim2: add sysfs property dci/node_address")
[7] https://github.com/microchip-ais/linux/commit/0494ccb4bc5f39
    ("staging: most: dim2: add sysfs property dci/ni_state")
[8] https://github.com/microchip-ais/linux/commit/3198a5c5f0663
    ("staging: most: dim2: add sysfs property dci/mep_eui48")

Re: [PATCH v4 12/12] staging: most: Documentation: update driver documentation

[Christian.Gromm]

On Mo, 2019-04-15 at 23:21 +0200, Eugeniu Rosca wrote:
> External E-Mail
> 
> 
> Hello Christian, hello Andrey,
> cc: Vladimir Barinov
> cc: linux-renesas-soc
> 
> Our team currently has the requirement of adding MOST support to
> the v4.14-based R-Car3 kernel [1], matching the level of features
> and interfaces of mld-1.8.0 [2] release.
> 
> Based on a quick check [3], the mld-1.8.0 release contains 221 non-
> merge
> non-mainline commits. It seems like at least some (most?) of them
> have
> been reworked during upstreaming and are now part of vanilla, thanks
> to
> your efforts.
> 
> Since you've actively participated in pushing the out-of-tree drivers
> to mainline, could you please share your gut feeling whether the
> current mainline state of the MOST subsystem matches the mld-1.8.0
> release in terms of features and interfaces?
> 

No, it doesn't. The version upstream does not have all the bells
and whistles the mld-1.8.0 version has, yet. Focus of the latest
mainline commits was on the driver model and the switch to configfs.

> At first glance, such mld-1.8.0 functionalities like "flexible PCM
> rate support" [4], as well as a number of dim2 sysfs entries [5-8]
> appear to be missing in v5.1-rc5. Could you please feedback if these
> have been deliberately dropped or didn't make their way for another
> reason? What would be your recommendation between going the mld-1.8.0
> and going the v5.1-rc5 way for MOST?
> 

The functionalities you're referring to have _not_ intentionally been
dropped. They will find their way into mainline. If there are urgent
feature requests, we could prioritize them.

Bottom line is, the upstream version is the one you should be using,
as it is going to replace the mld-1.x branch. This is exactly what we
will soon be doing for AGL by the way.

thanks,
Chris

Re: [PATCH v4 12/12] staging: most: Documentation: update driver documentation

[Eugeniu Rosca]

Hi Chris,

We really appreciate your feedback. Thanks for that.

For us going the vanilla way roughly means backporting to v4.14:
 - v5.1-rc5 MOST state (easy/straightforward)
 - MOST patches from either
   https://github.com/CogentEmbedded/meta-rcar/
   or https://github.com/microchip-ais/meta-medialb-rcar
 - A number of patches from mld-1.8.0

From the above list, the last step looks a bit more painful, but we
will try to deal with that.

If there are any mainline-relevant fixes developed on the way, we hope
to find some time to submit them to you and get feedback.

Best regards,
Eugeniu.

On Wed, Apr 17, 2019 at 01:45:41PM +0000, Christian.Gromm@microchip.com wrote:
> On Mo, 2019-04-15 at 23:21 +0200, Eugeniu Rosca wrote:
> > External E-Mail
> > 
> > 
> > Hello Christian, hello Andrey,
> > cc: Vladimir Barinov
> > cc: linux-renesas-soc
> > 
> > Our team currently has the requirement of adding MOST support to
> > the v4.14-based R-Car3 kernel [1], matching the level of features
> > and interfaces of mld-1.8.0 [2] release.
> > 
> > Based on a quick check [3], the mld-1.8.0 release contains 221 non-
> > merge
> > non-mainline commits. It seems like at least some (most?) of them
> > have
> > been reworked during upstreaming and are now part of vanilla, thanks
> > to
> > your efforts.
> > 
> > Since you've actively participated in pushing the out-of-tree drivers
> > to mainline, could you please share your gut feeling whether the
> > current mainline state of the MOST subsystem matches the mld-1.8.0
> > release in terms of features and interfaces?
> > 
> 
> No, it doesn't. The version upstream does not have all the bells
> and whistles the mld-1.8.0 version has, yet. Focus of the latest
> mainline commits was on the driver model and the switch to configfs.
> 
> > At first glance, such mld-1.8.0 functionalities like "flexible PCM
> > rate support" [4], as well as a number of dim2 sysfs entries [5-8]
> > appear to be missing in v5.1-rc5. Could you please feedback if these
> > have been deliberately dropped or didn't make their way for another
> > reason? What would be your recommendation between going the mld-1.8.0
> > and going the v5.1-rc5 way for MOST?
> > 
> 
> The functionalities you're referring to have _not_ intentionally been
> dropped. They will find their way into mainline. If there are urgent
> feature requests, we could prioritize them.
> 
> Bottom line is, the upstream version is the one you should be using,
> as it is going to replace the mld-1.x branch. This is exactly what we
> will soon be doing for AGL by the way.
> 
> thanks,
> Chris