From: Shravan Chippa <[email protected]>
Add new compatible name microchip,mpfs-pdma to support
out of order dma transfers
Reviewed-by: Conor Dooley <[email protected]>
Signed-off-by: Shravan Chippa <[email protected]>
---
.../bindings/dma/sifive,fu540-c000-pdma.yaml | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/Documentation/devicetree/bindings/dma/sifive,fu540-c000-pdma.yaml b/Documentation/devicetree/bindings/dma/sifive,fu540-c000-pdma.yaml
index a1af0b906365..974467c4bacb 100644
--- a/Documentation/devicetree/bindings/dma/sifive,fu540-c000-pdma.yaml
+++ b/Documentation/devicetree/bindings/dma/sifive,fu540-c000-pdma.yaml
@@ -27,10 +27,14 @@ allOf:
properties:
compatible:
- items:
- - enum:
- - sifive,fu540-c000-pdma
- - const: sifive,pdma0
+ oneOf:
+ - items:
+ - const: microchip,mpfs-pdma # Microchip out of order DMA transfer
+ - const: sifive,fu540-c000-pdma # Sifive in-order DMA transfer
+ - items:
+ - enum:
+ - sifive,fu540-c000-pdma
+ - const: sifive,pdma0
description:
Should be "sifive,<chip>-pdma" and "sifive,pdma<version>".
Supported compatible strings are -
--
2.34.1
On Tue, Oct 03, 2023 at 09:52:13AM +0530, shravan chippa wrote:
> From: Shravan Chippa <[email protected]>
>
> Add new compatible name microchip,mpfs-pdma to support
> out of order dma transfers
>
> Reviewed-by: Conor Dooley <[email protected]>
> Signed-off-by: Shravan Chippa <[email protected]>
> ---
> .../bindings/dma/sifive,fu540-c000-pdma.yaml | 12 ++++++++----
> 1 file changed, 8 insertions(+), 4 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/dma/sifive,fu540-c000-pdma.yaml b/Documentation/devicetree/bindings/dma/sifive,fu540-c000-pdma.yaml
> index a1af0b906365..974467c4bacb 100644
> --- a/Documentation/devicetree/bindings/dma/sifive,fu540-c000-pdma.yaml
> +++ b/Documentation/devicetree/bindings/dma/sifive,fu540-c000-pdma.yaml
> @@ -27,10 +27,14 @@ allOf:
>
> properties:
> compatible:
> - items:
> - - enum:
> - - sifive,fu540-c000-pdma
> - - const: sifive,pdma0
> + oneOf:
> + - items:
> + - const: microchip,mpfs-pdma # Microchip out of order DMA transfer
> + - const: sifive,fu540-c000-pdma # Sifive in-order DMA transfer
This doesn't really make sense. microchip,mpfs-pdma is compatible with
sifive,fu540-c000-pdma and sifive,fu540-c000-pdma is compatible with
sifive,pdma0, but microchip,mpfs-pdma is not compatible with
sifive,pdma0? (Or replace "compatible with" with "a superset of")
Any fallback is only useful if an OS only understanding the fallback
will work with the h/w. Does this h/w work without the driver changes?
Rob
Hi,
> -----Original Message-----
> From: Conor Dooley <[email protected]>
> Sent: Thursday, October 5, 2023 4:24 PM
> To: Rob Herring <[email protected]>
> Cc: shravan Chippa - I35088 <[email protected]>;
> [email protected]; [email protected]; [email protected];
> [email protected]; [email protected]; [email protected];
> [email protected]; [email protected]; linux-
> [email protected]; [email protected]; Nagasuresh Relli - I67208
> <[email protected]>; Praveen Kumar - I30718
> <[email protected]>; Conor Dooley - M52691
> <[email protected]>
> Subject: Re: [PATCH v2 2/4] dt-bindings: dma: sf-pdma: add new compatible
> name
>
> On Wed, Oct 04, 2023 at 08:30:21AM -0500, Rob Herring wrote:
> > On Tue, Oct 03, 2023 at 09:52:13AM +0530, shravan chippa wrote:
> > > From: Shravan Chippa <[email protected]>
> > >
> > > Add new compatible name microchip,mpfs-pdma to support out of order
> > > dma transfers
> > >
> > > Reviewed-by: Conor Dooley <[email protected]>
> > > Signed-off-by: Shravan Chippa <[email protected]>
> > > ---
> > > .../bindings/dma/sifive,fu540-c000-pdma.yaml | 12 ++++++++----
> > > 1 file changed, 8 insertions(+), 4 deletions(-)
> > >
> > > diff --git
> > > a/Documentation/devicetree/bindings/dma/sifive,fu540-c000-pdma.yaml
> > > b/Documentation/devicetree/bindings/dma/sifive,fu540-c000-pdma.yaml
> > > index a1af0b906365..974467c4bacb 100644
> > > ---
> > > a/Documentation/devicetree/bindings/dma/sifive,fu540-c000-pdma.yaml
> > > +++ b/Documentation/devicetree/bindings/dma/sifive,fu540-c000-pdma.y
> > > +++ aml
> > > @@ -27,10 +27,14 @@ allOf:
> > >
> > > properties:
> > > compatible:
> > > - items:
> > > - - enum:
> > > - - sifive,fu540-c000-pdma
> > > - - const: sifive,pdma0
> > > + oneOf:
> > > + - items:
> > > + - const: microchip,mpfs-pdma # Microchip out of order DMA transfer
> > > + - const: sifive,fu540-c000-pdma # Sifive in-order DMA
> > > + transfer
>
> IIRC I asked for the comments here to be removed on the previous version, and
> my r-b was conditional on that.
> The device specific compatible has merit outside of the ordering, which may just
> be a software policy decision.
>
> > This doesn't really make sense. microchip,mpfs-pdma is compatible with
> > sifive,fu540-c000-pdma and sifive,fu540-c000-pdma is compatible with
> > sifive,pdma0, but microchip,mpfs-pdma is not compatible with
> > sifive,pdma0? (Or replace "compatible with" with "a superset of")
>
> TBH, I am not sure why it was done this way. Probably because the driver
> contains both sifive,pdma0 and sifive,fu540-c000-pdma. Doing compatible =
> "microchip,mpfs-pdma", "sifive,fu540-c000-pdma", "sifive,pdma0"; thing would
> be fine.
>
> > Any fallback is only useful if an OS only understanding the fallback
> > will work with the h/w. Does this h/w work without the driver changes?
>
> Yes.
> I've been hoping that someone from SiFive would come along, and in response to
> this patchset, tell us _why_ the driver does not make use of out-of-order transfers
> to begin with.
>
I am also expecting a replay someone from SiFive
The out-of-order should work with other RISC-V platforms also.
I will try to send V3 with the below changes (just adding a new compatible name)
****************************
--- a/Documentation/devicetree/bindings/dma/sifive,fu540-c000-pdma.yaml
+++ b/Documentation/devicetree/bindings/dma/sifive,fu540-c000-pdma.yaml
@@ -29,6 +29,7 @@ properties:
compatible:
items:
- enum:
+ - microchip,mpfs-pdma
- sifive,fu540-c000-pdma
- const: sifive,pdma0
description:
***************************
Device tree patch
*****************************
--- a/arch/riscv/boot/dts/microchip/mpfs.dtsi
+++ b/arch/riscv/boot/dts/microchip/mpfs.dtsi
@@ -221,7 +221,7 @@ plic: interrupt-controller@c000000 {
};
pdma: dma-controller@3000000 {
- compatible = "sifive,fu540-c000-pdma", "sifive,pdma0";
+ compatible = "microchip,mpfs-pdma", "sifive,fu540-c000-pdma", "sifive,pdma0";
reg = <0x0 0x3000000 0x0 0x8000>;
interrupt-parent = <&plic>;
interrupts = <5 6>, <7 8>, <9 10>, <11 12>;
***************************
Thanks,
Shravan
> Thanks,
> Conor.
On Thu, Oct 12, 2023 at 09:22:17AM +0000, [email protected] wrote:
> Hi,
>
> > -----Original Message-----
> > From: Conor Dooley <[email protected]>
> > Sent: Thursday, October 5, 2023 4:24 PM
> > To: Rob Herring <[email protected]>
> > Cc: shravan Chippa - I35088 <[email protected]>;
> > [email protected]; [email protected]; [email protected];
> > [email protected]; [email protected]; [email protected];
> > [email protected]; [email protected]; linux-
> > [email protected]; [email protected]; Nagasuresh Relli - I67208
> > <[email protected]>; Praveen Kumar - I30718
> > <[email protected]>; Conor Dooley - M52691
> > <[email protected]>
> > Subject: Re: [PATCH v2 2/4] dt-bindings: dma: sf-pdma: add new compatible
> > name
> >
> > On Wed, Oct 04, 2023 at 08:30:21AM -0500, Rob Herring wrote:
> > > On Tue, Oct 03, 2023 at 09:52:13AM +0530, shravan chippa wrote:
> > > > From: Shravan Chippa <[email protected]>
> > > >
> > > > Add new compatible name microchip,mpfs-pdma to support out of order
> > > > dma transfers
> > > >
> > > > Reviewed-by: Conor Dooley <[email protected]>
> > > > Signed-off-by: Shravan Chippa <[email protected]>
> > > > ---
> > > > .../bindings/dma/sifive,fu540-c000-pdma.yaml | 12 ++++++++----
> > > > 1 file changed, 8 insertions(+), 4 deletions(-)
> > > >
> > > > diff --git
> > > > a/Documentation/devicetree/bindings/dma/sifive,fu540-c000-pdma.yaml
> > > > b/Documentation/devicetree/bindings/dma/sifive,fu540-c000-pdma.yaml
> > > > index a1af0b906365..974467c4bacb 100644
> > > > ---
> > > > a/Documentation/devicetree/bindings/dma/sifive,fu540-c000-pdma.yaml
> > > > +++ b/Documentation/devicetree/bindings/dma/sifive,fu540-c000-pdma.y
> > > > +++ aml
> > > > @@ -27,10 +27,14 @@ allOf:
> > > >
> > > > properties:
> > > > compatible:
> > > > - items:
> > > > - - enum:
> > > > - - sifive,fu540-c000-pdma
> > > > - - const: sifive,pdma0
> > > > + oneOf:
> > > > + - items:
> > > > + - const: microchip,mpfs-pdma # Microchip out of order DMA transfer
> > > > + - const: sifive,fu540-c000-pdma # Sifive in-order DMA
> > > > + transfer
> >
> > IIRC I asked for the comments here to be removed on the previous version, and
> > my r-b was conditional on that.
> > The device specific compatible has merit outside of the ordering, which may just
> > be a software policy decision.
> >
> > > This doesn't really make sense. microchip,mpfs-pdma is compatible with
> > > sifive,fu540-c000-pdma and sifive,fu540-c000-pdma is compatible with
> > > sifive,pdma0, but microchip,mpfs-pdma is not compatible with
> > > sifive,pdma0? (Or replace "compatible with" with "a superset of")
> >
> > TBH, I am not sure why it was done this way. Probably because the driver
> > contains both sifive,pdma0 and sifive,fu540-c000-pdma. Doing compatible =
> > "microchip,mpfs-pdma", "sifive,fu540-c000-pdma", "sifive,pdma0"; thing would
> > be fine.
> >
> > > Any fallback is only useful if an OS only understanding the fallback
> > > will work with the h/w. Does this h/w work without the driver changes?
> >
> > Yes.
> > I've been hoping that someone from SiFive would come along, and in response to
> > this patchset, tell us _why_ the driver does not make use of out-of-order transfers
> > to begin with.
> >
>
> I am also expecting a replay someone from SiFive
> The out-of-order should work with other RISC-V platforms also.
>
> I will try to send V3 with the below changes (just adding a new compatible name)
>
> ****************************
> --- a/Documentation/devicetree/bindings/dma/sifive,fu540-c000-pdma.yaml
> +++ b/Documentation/devicetree/bindings/dma/sifive,fu540-c000-pdma.yaml
> @@ -29,6 +29,7 @@ properties:
> compatible:
> items:
> - enum:
> + - microchip,mpfs-pdma
> - sifive,fu540-c000-pdma
> - const: sifive,pdma0
> description:
> ***************************
>
> Device tree patch
> *****************************
> --- a/arch/riscv/boot/dts/microchip/mpfs.dtsi
> +++ b/arch/riscv/boot/dts/microchip/mpfs.dtsi
> @@ -221,7 +221,7 @@ plic: interrupt-controller@c000000 {
> };
> pdma: dma-controller@3000000 {
> - compatible = "sifive,fu540-c000-pdma", "sifive,pdma0";
> + compatible = "microchip,mpfs-pdma", "sifive,fu540-c000-pdma", "sifive,pdma0";
This is gonna produce dtbs_check complaints. Your binding change only
permits `compatible = "microchip,mpfs-pdma", "sifive,pdma0";`
Cheers,
Conor.
> reg = <0x0 0x3000000 0x0 0x8000>;
> interrupt-parent = <&plic>;
> interrupts = <5 6>, <7 8>, <9 10>, <11 12>;
> ***************************
Hi Conor,
On 2023-10-05 5:54 AM, Conor Dooley wrote:
> On Wed, Oct 04, 2023 at 08:30:21AM -0500, Rob Herring wrote:
>> Any fallback is only useful if an OS only understanding the fallback
>> will work with the h/w. Does this h/w work without the driver changes?
>
> Yes.
> I've been hoping that someone from SiFive would come along, and in
> response to this patchset, tell us _why_ the driver does not make use of
> out-of-order transfers to begin with.
I have raised this question internally. So far I have not seen anything to
suggest we need strictly-ordered transfers either, but I still need to confirm this.
Regards,
Samuel