diff mbox series

[1/3] dt-bindings: usb: mtk-xhci: add a property for Gen1 isoc-in transfer issue

Message ID 20231213063543.12435-1-chunfeng.yun@mediatek.com
State New
Headers show
Series [1/3] dt-bindings: usb: mtk-xhci: add a property for Gen1 isoc-in transfer issue | expand

Commit Message

Chunfeng Yun (云春峰) Dec. 13, 2023, 6:35 a.m. UTC
For Gen1 isoc-in endpoint on controller before about SSUSB IPM v1.6.0, it
still send out unexpected ACK after receiving a short packet in burst
transfer, this will cause an exception on connected device, specially for
a 4k camera.
Add a quirk property "mediatek,rxfifo-depth" to work around this hardware
issue;
The side-effect is that may cause performance drop about 10%, including
bulk transfer.

Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
---
 .../devicetree/bindings/usb/mediatek,mtk-xhci.yaml     | 10 ++++++++++
 1 file changed, 10 insertions(+)

Comments

Chunfeng Yun (云春峰) Dec. 15, 2023, 6:10 a.m. UTC | #1
On Wed, 2023-12-13 at 09:05 +0100, Krzysztof Kozlowski wrote:
>  	 
> External email : Please do not click links or open attachments until
> you have verified the sender or the content.
>  On 13/12/2023 07:35, Chunfeng Yun wrote:
> > For Gen1 isoc-in endpoint on controller before about SSUSB IPM
> v1.6.0, it
> > still send out unexpected ACK after receiving a short packet in
> burst
> > transfer, this will cause an exception on connected device,
> specially for
> > a 4k camera.
> > Add a quirk property "mediatek,rxfifo-depth" to work around this
> hardware
> > issue;
> > The side-effect is that may cause performance drop about 10%,
> including
> > bulk transfer.
> > 
> > Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
> > ---
> >  .../devicetree/bindings/usb/mediatek,mtk-xhci.yaml     | 10
> ++++++++++
> >  1 file changed, 10 insertions(+)
> > 
> > diff --git a/Documentation/devicetree/bindings/usb/mediatek,mtk-
> xhci.yaml b/Documentation/devicetree/bindings/usb/mediatek,mtk-
> xhci.yaml
> > index e9644e333d78..b8ed68574ba4 100644
> > --- a/Documentation/devicetree/bindings/usb/mediatek,mtk-xhci.yaml
> > +++ b/Documentation/devicetree/bindings/usb/mediatek,mtk-xhci.yaml
> > @@ -124,6 +124,16 @@ properties:
> >        defined in the xHCI spec on MTK's controller.
> >      default: 5000
> >  
> > +  mediatek,rxfifo-depth:
> > +    description:
> 
> The property description and driver patch suggest you configure the
> depth of FIFO, so this should be not bool, but some uint32. And then,
> use generic "fifo-depth" property to set desired depth.
I fix it as 2, it's OK to use a uint32, I'll modify it.

Thanks

> 
> 
> Best regards,
> Krzysztof
> 
>
Chunfeng Yun (云春峰) Dec. 15, 2023, 6:14 a.m. UTC | #2
On Wed, 2023-12-13 at 12:17 +0100, AngeloGioacchino Del Regno wrote:
> Il 13/12/23 09:05, Krzysztof Kozlowski ha scritto:
> > On 13/12/2023 07:35, Chunfeng Yun wrote:
> > > For Gen1 isoc-in endpoint on controller before about SSUSB IPM
> > > v1.6.0, it
> > > still send out unexpected ACK after receiving a short packet in
> > > burst
> > > transfer, this will cause an exception on connected device,
> > > specially for
> > > a 4k camera.
> > > Add a quirk property "mediatek,rxfifo-depth" to work around this
> > > hardware
> > > issue;
> > > The side-effect is that may cause performance drop about 10%,
> > > including
> > > bulk transfer.
> > > 
> > > Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
> > > ---
> > >   .../devicetree/bindings/usb/mediatek,mtk-xhci.yaml     | 10
> > > ++++++++++
> > >   1 file changed, 10 insertions(+)
> > > 
> > > diff --git a/Documentation/devicetree/bindings/usb/mediatek,mtk-
> > > xhci.yaml b/Documentation/devicetree/bindings/usb/mediatek,mtk-
> > > xhci.yaml
> > > index e9644e333d78..b8ed68574ba4 100644
> > > --- a/Documentation/devicetree/bindings/usb/mediatek,mtk-
> > > xhci.yaml
> > > +++ b/Documentation/devicetree/bindings/usb/mediatek,mtk-
> > > xhci.yaml
> > > @@ -124,6 +124,16 @@ properties:
> > >         defined in the xHCI spec on MTK's controller.
> > >       default: 5000
> > >   
> > > +  mediatek,rxfifo-depth:
> > > +    description:
> > 
> > The property description and driver patch suggest you configure the
> > depth of FIFO, so this should be not bool, but some uint32. And
> > then,
> > use generic "fifo-depth" property to set desired depth.
> 
> Did you mean "rx-fifo-depth" instead, as used in net?
> This FIFO depth parameter is for RX only.
Yes, only for RX

> 
> Cheers,
> Angelo
> 
>
diff mbox series

Patch

diff --git a/Documentation/devicetree/bindings/usb/mediatek,mtk-xhci.yaml b/Documentation/devicetree/bindings/usb/mediatek,mtk-xhci.yaml
index e9644e333d78..b8ed68574ba4 100644
--- a/Documentation/devicetree/bindings/usb/mediatek,mtk-xhci.yaml
+++ b/Documentation/devicetree/bindings/usb/mediatek,mtk-xhci.yaml
@@ -124,6 +124,16 @@  properties:
       defined in the xHCI spec on MTK's controller.
     default: 5000
 
+  mediatek,rxfifo-depth:
+    description:
+      It is a quirk flag used to work around Gen1 isoc-in endpoint transfer
+      issue that still send out unexpected ACK after device finish the burst
+      transfer with a short packet and cause an exception, specially on a 4K
+      camera device, it happens on controller before about IPM v1.6.0; the
+      side-effect is that may cause performance drop about 10%, include bulk
+      transfer.
+    type: boolean
+
   # the following properties are only used for case 1
   wakeup-source:
     description: enable USB remote wakeup, see power/wakeup-source.txt