Re: [RFC v2] usb: xhci: add Immediate Data Transfer support

2019-02-06 Thread Felipe Balbi
Hi, Nicolas Saenz Julienne writes: >> > diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c >> > index 005e65922608..dec62f7f5dc8 100644 >> > --- a/drivers/usb/host/xhci.c >> > +++ b/drivers/usb/host/xhci.c >> > @@ -1238,6 +1238,21 @@ EXPORT_SYMBOL_GPL(xhci_resume); >> > >> > >> >

Re: [RFC v2] usb: xhci: add Immediate Data Transfer support

2019-02-06 Thread Nicolas Saenz Julienne
Hi Felipe, thanks for the review! On Wed, 2019-02-06 at 08:35 +0200, Felipe Balbi wrote: > Hi, > > Nicolas Saenz Julienne writes: > > diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c > > index 40fa25c4d041..a4efbe62a1a3 100644 > > --- a/drivers/usb/host/xhci-ring.c > > ++

Re: [RFC v2] usb: xhci: add Immediate Data Transfer support

2019-02-05 Thread Felipe Balbi
Hi, Nicolas Saenz Julienne writes: > diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c > index 40fa25c4d041..a4efbe62a1a3 100644 > --- a/drivers/usb/host/xhci-ring.c > +++ b/drivers/usb/host/xhci-ring.c > @@ -3272,8 +3272,15 @@ int xhci_queue_bulk_tx(struct xhci_hcd *xhci,

[RFC v2] usb: xhci: add Immediate Data Transfer support

2019-02-05 Thread Nicolas Saenz Julienne
Immediate data transfers (IDT) allow the HCD to copy small chunks of data (up to 8bytes) directly into its output transfer TRBs. This avoids the somewhat expensive DMA mappings that are performed by default on most URBs submissions. In the case an URB was suitable for IDT. The data is directly cop