Re: [PATCHv5 0/2] Fix imx53-ppd UART configuration

Re: [PATCHv5 0/2] Fix imx53-ppd UART configuration

[Uwe Kleine-König]

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Hello Greg,

[adding Rob and devicetree@vger to Cc:]

On Fri, May 28, 2021 at 11:03:54AM +0200, Greg Kroah-Hartman wrote:
> On Fri, May 28, 2021 at 02:49:52AM +0200, Sebastian Reichel wrote:
> > On Sat, May 01, 2021 at 08:11:52AM +0200, Greg Kroah-Hartman wrote:
> > > On Fri, Apr 30, 2021 at 07:50:36PM +0200, Sebastian Reichel wrote:
> > > > IMHO PATCHv4 was better, but in the end I don't have strong feelings
> > > > about this. Btw. I think this patchset is a good demonstration of
> > > > frustrating upstream kernel development can be considering PATCHv5
> > > > is basically the same as PATCHv1. Thanks for making us go in
> > > > circles :(

I was the one who objected the v1 approach. My frustration is that I
wasn't Cc:d in the later iterations of this patch set. And I also liked
v4 better :-\

> > > > Changes since PATCHv4:
> > > >  * https://lore.kernel.org/lkml/20210305115058.92284-1-sebastian.reichel@collabora.com/
> > > >  * use DT property instead of sysfs config option, like the initial patch
> > > >    version did as requested by Greg.
> > > > 
> > > > Changes since PATCHv3:
> > > >  * https://lore.kernel.org/lkml/1539249903-6316-1-git-send-email-fabien.lahoudere@collabora.com/
> > > >  * rewrote commit message to provide a lot more details why this is needed
> > > >  * rebased to torvalds/master (5.12-rc1-dontuse), also applies on top of linux-next
> > > >  * use sysfs_emit() instead of sprintf
> > > > 
> > > > -- Sebastian
> > > > 
> > > > Fabien Lahoudere (2):
> > > >   serial: imx: Add DMA buffer configuration via DT
> > > >   ARM: dts: imx53-ppd: add dma-info nodes
> > > > 
> > > >  .../bindings/serial/fsl-imx-uart.yaml         | 12 +++++++++
> > > >  arch/arm/boot/dts/imx53-ppd.dts               |  2 ++
> > > >  drivers/tty/serial/imx.c                      | 25 +++++++++++++------
> > > >  3 files changed, 32 insertions(+), 7 deletions(-)
> > >
> > > This is the friendly semi-automated patch-bot of Greg Kroah-Hartman.
> > > You have sent him a patch that has triggered this response.
> > > 
> > > Right now, the development tree you have sent a patch for is "closed"
> > > due to the timing of the merge window.  Don't worry, the patch(es) you
> > > have sent are not lost, and will be looked at after the merge window is
> > > over (after the -rc1 kernel is released by Linus).
> > > 
> > > So thank you for your patience and your patches will be reviewed at this
> > > later time, you do not have to do anything further, this is just a short
> > > note to let you know the patch status and so you don't worry they didn't
> > > make it through.
> > > 
> > > thanks,
> > > 
> > > greg k-h's patch email bot
> > 
> > Any update on this? :)
> 
> I'm waiting for the DT maintainers to review the new changes before I
> can take the driver changes.

I wonder what the DT maintainers said (and where [1]). The patch was
applied (db0a196bd8ad1d6bb4b1a9e54f54c09f8dc2cc25) and I think that's
wrong (as it was in v1) because fsl,dma-info isn't about hardware
description but about software tuning for different use cases.

Best regards
Uwe

[1] neither my mailbox nor lore.kernel.org know about an answer.

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | https://www.pengutronix.de/ |

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Re: [PATCHv5 0/2] Fix imx53-ppd UART configuration

[Uwe Kleine-König]

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[Cc += dt maintainers]

On Fri, Apr 30, 2021 at 07:50:36PM +0200, Sebastian Reichel wrote:
> IMHO PATCHv4 was better, but in the end I don't have strong feelings
> about this. Btw. I think this patchset is a good demonstration of
> frustrating upstream kernel development can be considering PATCHv5
> is basically the same as PATCHv1. Thanks for making us go in
> circles :(

I still like v4 better than v1/v5. I'm sorry for the frustration this
created on your side. 

I'd ask Greg to reconsider given that dt is less flexible than a sysfs
knob and otherwise shares all downsides of sysfs (people don't want to
have to tune that, so a useful default for most cases is important; you
have to consult documentation to understand how to tune it).

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | https://www.pengutronix.de/ |

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Re: [PATCHv5 0/2] Fix imx53-ppd UART configuration

[Greg Kroah-Hartman]

On Fri, Dec 08, 2023 at 10:07:54AM +0100, Uwe Kleine-König wrote:
> [Cc += dt maintainers]
> 
> On Fri, Apr 30, 2021 at 07:50:36PM +0200, Sebastian Reichel wrote:

You are responding to a message from 2021???

I can't remember what I wrote in an email last week, let alone years
ago, are you sure any of this is relevant still?

thanks,

greg k-h

Re: [PATCHv5 0/2] Fix imx53-ppd UART configuration

[Krzysztof Kozlowski]

On 08/12/2023 11:32, Greg Kroah-Hartman wrote:
> On Fri, Dec 08, 2023 at 10:07:54AM +0100, Uwe Kleine-König wrote:
>> [Cc += dt maintainers]
>>
>> On Fri, Apr 30, 2021 at 07:50:36PM +0200, Sebastian Reichel wrote:
> 
> You are responding to a message from 2021???
> 
> I can't remember what I wrote in an email last week, let alone years
> ago, are you sure any of this is relevant still?
> 

Also, adding DT maintainers as Cc, does not magically allow us to
understand the discussion. Please shortly summarize what do you
need/expect from us.

Best regards,
Krzysztof

Re: EXT: Re: [PATCHv5 0/2] Fix imx53-ppd UART configuration

[Ian Ray]

On Fri, Dec 08, 2023 at 01:14:50PM +0100, Krzysztof Kozlowski wrote:
> 
> On 08/12/2023 11:32, Greg Kroah-Hartman wrote:
> > On Fri, Dec 08, 2023 at 10:07:54AM +0100, Uwe Kleine-K??nig wrote:
> >> [Cc += dt maintainers]
> >>
> >> On Fri, Apr 30, 2021 at 07:50:36PM +0200, Sebastian Reichel wrote:
> > 
> > You are responding to a message from 2021???
> > 
> > I can't remember what I wrote in an email last week, let alone years
> > ago, are you sure any of this is relevant still?
> > 
> 
> Also, adding DT maintainers as Cc, does not magically allow us to
> understand the discussion. Please shortly summarize what do you
> need/expect from us.

This thread is indeed old, but we are remain interested in getting
this resolved.


The topic itself is about the tuning of DMA buffers for the i.MX53
platform.

DMA is required (for the 4M baud UART case), and a specific buffer
configuration is required, too.


Two approaches have been attempted:

"V4" sysfs
https://lore.kernel.org/lkml/20210305115058.92284-1-sebastian.reichel@collabora.com/

"V5" DT
https://lore.kernel.org/lkml/20210430175038.103226-1-sebastian.reichel@collabora.com/
(this thread)


Uwe recently commented to [1], and (hoping to avoid any further
confusion) let's continue in that thread.

[1] https://lore.kernel.org/lkml/20231208090205.ioc76sych3snjiwb@pengutronix.de/


> 
> Best regards,
> Krzysztof
> 
>