2024-02-05 18:51:28

by Stefan Wahren

[permalink] [raw]
Subject: Re: [PATCH 02/12] bcm2835-dma: Add proper 40-bit DMA support

Hi Andrea,

[add Dave]

Am 04.02.24 um 07:59 schrieb Andrea della Porta:
> From: Phil Elwell <[email protected]>
>
> BCM2711 has 4 DMA channels with a 40-bit address range, allowing them
> to access the full 4GB of memory on a Pi 4.
>
> Cc: Phil Elwell <[email protected]>
> Cc: Maxime Ripard <[email protected]>
> Signed-off-by: Andrea della Porta <[email protected]>
mainlining isn't that simple by sending just the downstream patches to
the mailing list. In many cases there reasons why this hasn't been
upstreamed yet.

In my opinion just this feature is worth a separate patch series. In
2021 i already send an initial version, which tried to implement it in a
cleaner & maintainabler way [1]. In the meantime Dave Stevenson from
Raspberry Pi wrote that he also wanted to work on this. Maybe you want
to work on this together?

[1] -
https://lore.kernel.org/linux-arm-kernel/[email protected]/T/


2024-02-06 16:31:33

by Dave Stevenson

[permalink] [raw]
Subject: Re: [PATCH 02/12] bcm2835-dma: Add proper 40-bit DMA support

Hi Stefan and Andrea

On Mon, 5 Feb 2024 at 18:50, Stefan Wahren <[email protected]> wrote:
>
> Hi Andrea,
>
> [add Dave]
>
> Am 04.02.24 um 07:59 schrieb Andrea della Porta:
> > From: Phil Elwell <[email protected]>
> >
> > BCM2711 has 4 DMA channels with a 40-bit address range, allowing them
> > to access the full 4GB of memory on a Pi 4.
> >
> > Cc: Phil Elwell <[email protected]>
> > Cc: Maxime Ripard <[email protected]>
> > Signed-off-by: Andrea della Porta <[email protected]>
> mainlining isn't that simple by sending just the downstream patches to
> the mailing list. In many cases there reasons why this hasn't been
> upstreamed yet.
>
> In my opinion just this feature is worth a separate patch series. In
> 2021 i already send an initial version, which tried to implement it in a
> cleaner & maintainabler way [1]. In the meantime Dave Stevenson from
> Raspberry Pi wrote that he also wanted to work on this. Maybe you want
> to work on this together?

Yes, I'm looking at reworking Stefan's series to work on Pi4 & Pi5 as
it's needed for HDMI audio (and other things) on those platforms which
I'm working to upstream.

I was getting weirdness from the sdhci block when I was last looking
at it, so it was just proving a little trickier than first thought.
Hopefully I'll get some time on it in the next couple of weeks.

Dave

> [1] -
> https://lore.kernel.org/linux-arm-kernel/[email protected]/T/

2024-02-06 18:09:19

by Stefan Wahren

[permalink] [raw]
Subject: Re: [PATCH 02/12] bcm2835-dma: Add proper 40-bit DMA support

Hi Dave and Andrea,

Am 06.02.24 um 17:31 schrieb Dave Stevenson:
> Hi Stefan and Andrea
>
> On Mon, 5 Feb 2024 at 18:50, Stefan Wahren <[email protected]> wrote:
>> Hi Andrea,
>>
>> [add Dave]
>>
>> Am 04.02.24 um 07:59 schrieb Andrea della Porta:
>>> From: Phil Elwell <[email protected]>
>>>
>>> BCM2711 has 4 DMA channels with a 40-bit address range, allowing them
>>> to access the full 4GB of memory on a Pi 4.
>>>
>>> Cc: Phil Elwell <[email protected]>
>>> Cc: Maxime Ripard <[email protected]>
>>> Signed-off-by: Andrea della Porta <[email protected]>
>> mainlining isn't that simple by sending just the downstream patches to
>> the mailing list. In many cases there reasons why this hasn't been
>> upstreamed yet.
>>
>> In my opinion just this feature is worth a separate patch series. In
>> 2021 i already send an initial version, which tried to implement it in a
>> cleaner & maintainabler way [1]. In the meantime Dave Stevenson from
>> Raspberry Pi wrote that he also wanted to work on this. Maybe you want
>> to work on this together?
> Yes, I'm looking at reworking Stefan's series to work on Pi4 & Pi5 as
> it's needed for HDMI audio (and other things) on those platforms which
> I'm working to upstream.
>
> I was getting weirdness from the sdhci block when I was last looking
> at it, so it was just proving a little trickier than first thought.
> Hopefully I'll get some time on it in the next couple of weeks.
i must confess that my series was just a draft to see that the general
approach would be accepted. Yes, it's possible that there are issues :-(

Maybe i can help you a little bit by taking care of first two patches
(node name fix & YAML conversion)?

Regards
> Dave
>
>> [1] -
>> https://lore.kernel.org/linux-arm-kernel/[email protected]/T/


2024-02-06 18:12:05

by Stefan Wahren

[permalink] [raw]
Subject: Re: [PATCH 02/12] bcm2835-dma: Add proper 40-bit DMA support

Am 06.02.24 um 19:08 schrieb Stefan Wahren:
> Hi Dave and Andrea,
>
> Am 06.02.24 um 17:31 schrieb Dave Stevenson:
>> Hi Stefan and Andrea
>>
>> On Mon, 5 Feb 2024 at 18:50, Stefan Wahren <[email protected]> wrote:
>>> Hi Andrea,
>>>
>>> [add Dave]
>>>
>>> Am 04.02.24 um 07:59 schrieb Andrea della Porta:
>>>> From: Phil Elwell <[email protected]>
>>>>
>>>> BCM2711 has 4 DMA channels with a 40-bit address range, allowing them
>>>> to access the full 4GB of memory on a Pi 4.
>>>>
>>>> Cc: Phil Elwell <[email protected]>
>>>> Cc: Maxime Ripard <[email protected]>
>>>> Signed-off-by: Andrea della Porta <[email protected]>
>>> mainlining isn't that simple by sending just the downstream patches to
>>> the mailing list. In many cases there reasons why this hasn't been
>>> upstreamed yet.
>>>
>>> In my opinion just this feature is worth a separate patch series. In
>>> 2021 i already send an initial version, which tried to implement it
>>> in a
>>> cleaner & maintainabler way [1]. In the meantime Dave Stevenson from
>>> Raspberry Pi wrote that he also wanted to work on this. Maybe you want
>>> to work on this together?
>> Yes, I'm looking at reworking Stefan's series to work on Pi4 & Pi5 as
>> it's needed for HDMI audio (and other things) on those platforms which
>> I'm working to upstream.
>>
>> I was getting weirdness from the sdhci block when I was last looking
>> at it, so it was just proving a little trickier than first thought.
>> Hopefully I'll get some time on it in the next couple of weeks.
> i must confess that my series was just a draft to see that the general
> approach would be accepted. Yes, it's possible that there are issues :-(
>
> Maybe i can help you a little bit by taking care of first two patches
> (node name fix & YAML conversion)?
Forget about this, it's already done
>
> Regards
>>    Dave
>>
>>> [1] -
>>> https://lore.kernel.org/linux-arm-kernel/[email protected]/T/
>>>
>