[U-Boot] [UBOOT RFC PATCH 13/13] dwc3: core: Change the bounce buffer size to 4096

Felipe Balbi
2014-08-22T13:54:13Z

On Fri, Aug 22, 2014 at 04:32:10PM +0530, Kishon Vijay Abraham I wrote:
> Hi,
>
> On Tuesday 19 August 2014 09:57 PM, Felipe Balbi wrote:
> > On Tue, Aug 19, 2014 at 09:45:11PM +0530, Kishon Vijay Abraham I wrote:
> >> Hi,
> >>
> >> On Monday 18 August 2014 08:11 PM, Felipe Balbi wrote:
> >>> On Mon, Aug 18, 2014 at 07:58:35PM +0530, Kishon Vijay Abraham I wrote:
> >>>> Bounce buffer is used for transferring requests which is not maxpacket
> >>>> aligned. In the case of DFU the requests can be upto 4096 bytes.
> >>>>
> >>>> While the actual fix for this should be using two chained TRBs to handle
> >>>> the transfer, this can be used as a temporary fix.
> >>>
> >>> Did you manage to trigger this fault ? Was the size larger than 512 ?
> >>
> >> yeah.. transferring any kernel image resulted in a size larger than 512.
> >
> > but it's also larger than 4KiB :-)
>
> Yeah. But the DFU specifies the maximum transfer size in wTransferSize (DFU
> function descriptor) to the host which is 4096 bytes (DFU_USB_BUFSIZ).
>
> So the max size will be only 4KB.

ah, ok. Thanks for that detail.

--
balbi
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