Re: [PATCH 1/1 linux-next] zd1201: replace kmalloc/memset by kzalloc

[Fabian Frederick]

> On 14 October 2014 at 20:08 BjÃrn Mork <bjorn@xxxxxxx> wrote:
>
>
> Joe Perches <joe@xxxxxxxxxxx> writes:
>
> > And does this really need to be alloc'd?
>
> Yes, it does. It is used as a transfer_buffer in usb_fill_bulk_urb() and
> must be "suitable for DMA". From include/linux/usb.h:
>
> /**
>Â * struct urb - USB Request Block
> ..
>Â * @transfer_buffer:Â This identifies the buffer to (or from) which the I/O
>Â *Â Â Â request will be performed unless URB_NO_TRANSFER_DMA_MAP is set
>Â *Â Â Â (however, do not leave garbage in transfer_buffer even then).
>Â *Â Â Â This buffer must be suitable for DMA; allocate it with
> *   kmalloc() or equivalent. For transfers to "in" endpoints, contents
> *   of this buffer will be modified. This buffer is used for the data
>Â *Â Â Â stage of control transfers.
>
>

Adding a structure would be a nice design update indeed but this would require
some testing...Separate patch maybe ?
Â
Fabian

>
> BjÃrn
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