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[5/7] arm64: dts: ti: k3-am62-verdin: Drop McASP AFIFOs

Message ID 20240604-mcasp_fifo_drop-v1-5-03ebe25f47db@ti.com (mailing list archive)
State New, archived
Headers show
Series arm64: dts: ti: McASP fixes | expand

Commit Message

Jai Luthra June 4, 2024, 9:41 a.m. UTC
McASP AFIFOs are not necessary with UDMA-P/BCDMA as there is buffering
on the DMA IP. Drop these for better audio latency.

Fixes: 316b80246b16 ("arm64: dts: ti: add verdin am62")
Signed-off-by: Jai Luthra <j-luthra@ti.com>
---
 arch/arm64/boot/dts/ti/k3-am62-verdin.dtsi | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

Comments

Francesco Dolcini June 5, 2024, 8:47 a.m. UTC | #1
Hello Jai, thanks for the patch.

On Tue, Jun 04, 2024 at 03:11:06PM +0530, Jai Luthra wrote:
> McASP AFIFOs are not necessary with UDMA-P/BCDMA as there is buffering
> on the DMA IP. Drop these for better audio latency.
> 
> Fixes: 316b80246b16 ("arm64: dts: ti: add verdin am62")
> Signed-off-by: Jai Luthra <j-luthra@ti.com>
> ---
>  arch/arm64/boot/dts/ti/k3-am62-verdin.dtsi | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/arm64/boot/dts/ti/k3-am62-verdin.dtsi b/arch/arm64/boot/dts/ti/k3-am62-verdin.dtsi
> index 2038c5e04639..27e5220e1dc7 100644
> --- a/arch/arm64/boot/dts/ti/k3-am62-verdin.dtsi
> +++ b/arch/arm64/boot/dts/ti/k3-am62-verdin.dtsi
> @@ -1364,8 +1364,8 @@ &mcasp0 {
>  	       0 0 0 0
>  	>;
>  	tdm-slots = <2>;
> -	rx-num-evt = <32>;
> -	tx-num-evt = <32>;
> +	rx-num-evt = <0>;
> +	tx-num-evt = <0>;

From my understanding of the dt-binding having these properties set to
<0> is equivalent to not having those properties at all.
My suggestion would be to just remove those, therefore.

With that said, in any case, whatever you do my suggested change or not,

Acked-by: Francesco Dolcini <francesco.dolcini@toradex.com>

Francesco
Jai Luthra June 5, 2024, 8:58 a.m. UTC | #2
Hi Francesco,

Thanks for the review.

On Jun 05, 2024 at 10:47:13 +0200, Francesco Dolcini wrote:
> Hello Jai, thanks for the patch.
> 
> On Tue, Jun 04, 2024 at 03:11:06PM +0530, Jai Luthra wrote:
> > McASP AFIFOs are not necessary with UDMA-P/BCDMA as there is buffering
> > on the DMA IP. Drop these for better audio latency.
> > 
> > Fixes: 316b80246b16 ("arm64: dts: ti: add verdin am62")
> > Signed-off-by: Jai Luthra <j-luthra@ti.com>
> > ---
> >  arch/arm64/boot/dts/ti/k3-am62-verdin.dtsi | 8 ++++----
> >  1 file changed, 4 insertions(+), 4 deletions(-)
> > 
> > diff --git a/arch/arm64/boot/dts/ti/k3-am62-verdin.dtsi b/arch/arm64/boot/dts/ti/k3-am62-verdin.dtsi
> > index 2038c5e04639..27e5220e1dc7 100644
> > --- a/arch/arm64/boot/dts/ti/k3-am62-verdin.dtsi
> > +++ b/arch/arm64/boot/dts/ti/k3-am62-verdin.dtsi
> > @@ -1364,8 +1364,8 @@ &mcasp0 {
> >  	       0 0 0 0
> >  	>;
> >  	tdm-slots = <2>;
> > -	rx-num-evt = <32>;
> > -	tx-num-evt = <32>;
> > +	rx-num-evt = <0>;
> > +	tx-num-evt = <0>;
> 
> From my understanding of the dt-binding having these properties set to
> <0> is equivalent to not having those properties at all.
> My suggestion would be to just remove those, therefore.
> 

I was following the existing convention of setting it to 0 for 
disabling, as done in k3-j721e-common-proc-board.dts

IMO it is better to keep it explicit, but I don't feel strongly against 
dropping it either (as long as we do the same for j721e). Will defer the 
decision to the tree maintainers.

> With that said, in any case, whatever you do my suggested change or 
> not,
> 
> Acked-by: Francesco Dolcini <francesco.dolcini@toradex.com>
> 
> Francesco
>
Nishanth Menon June 5, 2024, 12:52 p.m. UTC | #3
On 14:28-20240605, Jai Luthra wrote:
> Hi Francesco,
> 
> Thanks for the review.
> 
> On Jun 05, 2024 at 10:47:13 +0200, Francesco Dolcini wrote:
> > Hello Jai, thanks for the patch.
> > 
> > On Tue, Jun 04, 2024 at 03:11:06PM +0530, Jai Luthra wrote:
> > > McASP AFIFOs are not necessary with UDMA-P/BCDMA as there is buffering
> > > on the DMA IP. Drop these for better audio latency.
> > > 
> > > Fixes: 316b80246b16 ("arm64: dts: ti: add verdin am62")
> > > Signed-off-by: Jai Luthra <j-luthra@ti.com>
> > > ---
> > >  arch/arm64/boot/dts/ti/k3-am62-verdin.dtsi | 8 ++++----
> > >  1 file changed, 4 insertions(+), 4 deletions(-)
> > > 
> > > diff --git a/arch/arm64/boot/dts/ti/k3-am62-verdin.dtsi b/arch/arm64/boot/dts/ti/k3-am62-verdin.dtsi
> > > index 2038c5e04639..27e5220e1dc7 100644
> > > --- a/arch/arm64/boot/dts/ti/k3-am62-verdin.dtsi
> > > +++ b/arch/arm64/boot/dts/ti/k3-am62-verdin.dtsi
> > > @@ -1364,8 +1364,8 @@ &mcasp0 {
> > >  	       0 0 0 0
> > >  	>;
> > >  	tdm-slots = <2>;
> > > -	rx-num-evt = <32>;
> > > -	tx-num-evt = <32>;
> > > +	rx-num-evt = <0>;
> > > +	tx-num-evt = <0>;
> > 
> > From my understanding of the dt-binding having these properties set to
> > <0> is equivalent to not having those properties at all.
> > My suggestion would be to just remove those, therefore.
> > 
> 
> I was following the existing convention of setting it to 0 for 
> disabling, as done in k3-j721e-common-proc-board.dts
> 
> IMO it is better to keep it explicit, but I don't feel strongly against 
> dropping it either (as long as we do the same for j721e). Will defer the 
> decision to the tree maintainers.
> 

If they are equivalent, then just drop them.
diff mbox series

Patch

diff --git a/arch/arm64/boot/dts/ti/k3-am62-verdin.dtsi b/arch/arm64/boot/dts/ti/k3-am62-verdin.dtsi
index 2038c5e04639..27e5220e1dc7 100644
--- a/arch/arm64/boot/dts/ti/k3-am62-verdin.dtsi
+++ b/arch/arm64/boot/dts/ti/k3-am62-verdin.dtsi
@@ -1364,8 +1364,8 @@  &mcasp0 {
 	       0 0 0 0
 	>;
 	tdm-slots = <2>;
-	rx-num-evt = <32>;
-	tx-num-evt = <32>;
+	rx-num-evt = <0>;
+	tx-num-evt = <0>;
 	#sound-dai-cells = <0>;
 	status = "disabled";
 };
@@ -1382,8 +1382,8 @@  &mcasp1 {
 	       0 0 0 0
 	>;
 	tdm-slots = <2>;
-	rx-num-evt = <32>;
-	tx-num-evt = <32>;
+	rx-num-evt = <0>;
+	tx-num-evt = <0>;
 	#sound-dai-cells = <0>;
 	status = "disabled";
 };