On Wed, May 27, 2020 at 04:10:55PM +0530, Tejas Joglekar wrote: > This commit adds the documentation for sgl-trb-cache-size-quirk, and > snps,sgl-trb-cache-size-quirk property. These when set enables the > quirk for XHCI driver for consolidation of sg list into a temporary > buffer when small buffer sizes are scattered over the sg list not > making up to MPS or total transfer size within TRB cache size with > Synopsys xHC. > > Signed-off-by: Tejas Joglekar <joglekar@xxxxxxxxxxxx> > --- > Documentation/devicetree/bindings/usb/dwc3.txt | 4 ++++ > Documentation/devicetree/bindings/usb/usb-xhci.txt | 3 +++ > 2 files changed, 7 insertions(+) > > diff --git a/Documentation/devicetree/bindings/usb/dwc3.txt b/Documentation/devicetree/bindings/usb/dwc3.txt > index d03edf9d3935..0fcbaa51f66e 100644 > --- a/Documentation/devicetree/bindings/usb/dwc3.txt > +++ b/Documentation/devicetree/bindings/usb/dwc3.txt > @@ -102,6 +102,10 @@ Optional properties: > this and tx-thr-num-pkt-prd to a valid, non-zero value > 1-16 (DWC_usb31 programming guide section 1.2.3) to > enable periodic ESS TX threshold. > + - snps,sgl-trb-cache-size-quirk: enable sg list consolidation - host mode > + only. Set to use SG buffers of at least MPS size > + by consolidating smaller SG buffers list into a > + single buffer. > > - <DEPRECATED> tx-fifo-resize: determines if the FIFO *has* to be reallocated. > - snps,incr-burst-type-adjustment: Value for INCR burst type of GSBUSCFG0 > diff --git a/Documentation/devicetree/bindings/usb/usb-xhci.txt b/Documentation/devicetree/bindings/usb/usb-xhci.txt > index dc025f126d71..c53eb19ae67e 100644 > --- a/Documentation/devicetree/bindings/usb/usb-xhci.txt > +++ b/Documentation/devicetree/bindings/usb/usb-xhci.txt > @@ -44,6 +44,9 @@ Optional properties: > - quirk-broken-port-ped: set if the controller has broken port disable mechanism > - imod-interval-ns: default interrupt moderation interval is 5000ns > - phys : see usb-hcd.yaml in the current directory > + - sgl-trb-cache-size-quirk: set if you need to consolidate sg list into a > + temporary buffer when small SG buffer sizes does not make upto MPS > + size or total transfer size across the TRB cache size. Still don't understand why you have 2 properties? Is this a generic issue for multiple XHCI controllers? If yes, you don't need the first one. If no, then you don't need the second one. Really, I'd prefer neither, and this should be implied by a specific compatible string. Having a separate property doesn't work if you find this issue later on after already adding XHCI support. IOW, don't make users update their DT to handle a quirk. Rob
