Re: [PATCH] xhci: Set DMA parameters appropriately

2017-10-17 Thread Marek Szyprowski
Hi Robin, On 2017-10-13 12:48, Robin Murphy wrote: On 13/10/17 09:15, Marek Szyprowski wrote: On 2017-10-11 15:56, Robin Murphy wrote: xHCI requires that data buffers do not cross 64KB boundaries (and are thus at most 64KB long as well) - whilst xhci_queue_{bulk,isoc}_tx() already split their

Re: [PATCH] xhci: Set DMA parameters appropriately

2017-10-13 Thread Robin Murphy
Hi Marek, On 13/10/17 09:15, Marek Szyprowski wrote: > Hi Robin, > > On 2017-10-11 15:56, Robin Murphy wrote: >> xHCI requires that data buffers do not cross 64KB boundaries (and are >> thus at most 64KB long as well) - whilst xhci_queue_{bulk,isoc}_tx() >> already split their input buffers into

Re: [PATCH] xhci: Set DMA parameters appropriately

2017-10-13 Thread Marek Szyprowski
Hi Robin, On 2017-10-11 15:56, Robin Murphy wrote: xHCI requires that data buffers do not cross 64KB boundaries (and are thus at most 64KB long as well) - whilst xhci_queue_{bulk,isoc}_tx() already split their input buffers into individual TRBs as necessary, it's still a good idea to advertise t

[PATCH] xhci: Set DMA parameters appropriately

2017-10-11 Thread Robin Murphy
xHCI requires that data buffers do not cross 64KB boundaries (and are thus at most 64KB long as well) - whilst xhci_queue_{bulk,isoc}_tx() already split their input buffers into individual TRBs as necessary, it's still a good idea to advertise the limitations via the standard DMA API mechanism, so