Re: [PATCH 1/9] usb: gadget: add generic map/unmap request utilities

[Felipe Balbi]

Hi,

On Mon, Dec 19, 2011 at 10:19:46AM -0500, Alan Stern wrote:
> On Mon, 19 Dec 2011, Felipe Balbi wrote:
> 
> > such utilities are currently duplicated on all UDC
> > drivers basically with the same structure. Let's group
> > all implementations into one generic implementation
> > and get rid of that duplication.
> > 
> > Signed-off-by: Felipe Balbi <balbi@xxxxxx>
> > ---
> >  drivers/usb/gadget/udc-core.c |   53 +++++++++++++++++++++++++++++++++++++++++
> >  include/linux/usb/gadget.h    |   10 +++++++
> >  2 files changed, 63 insertions(+), 0 deletions(-)
> > 
> > diff --git a/drivers/usb/gadget/udc-core.c b/drivers/usb/gadget/udc-core.c
> > index 0b0d12c..2031c11 100644
> > --- a/drivers/usb/gadget/udc-core.c
> > +++ b/drivers/usb/gadget/udc-core.c
> > @@ -22,6 +22,7 @@
> >  #include <linux/device.h>
> >  #include <linux/list.h>
> >  #include <linux/err.h>
> > +#include <linux/dma-mapping.h>
> >  
> >  #include <linux/usb/ch9.h>
> >  #include <linux/usb/gadget.h>
> > @@ -49,6 +50,58 @@ static DEFINE_MUTEX(udc_lock);
> >  
> >  /* ------------------------------------------------------------------------- */
> >  
> > +int usb_gadget_map_request(struct usb_gadget *gadget,
> > +		struct usb_request *req, int direction)
> > +{
> > +	if (req->length == 0)
> > +		return 0;
> > +
> > +	if (req->num_sgs) {
> > +		int     mapped;
> > +
> > +		mapped = dma_map_sg(&gadget->dev, req->sg, req->num_sgs,
> > +				direction ? DMA_TO_DEVICE
> > +				: DMA_FROM_DEVICE);
> > +		if (mapped == 0) {
> > +			dev_err(&gadget->dev, "failed to map SGs\n");
> > +			return -EFAULT;
> > +		}
> > +
> > +		req->num_mapped_sgs = mapped;
> > +	} else {
> > +		req->dma = dma_map_single(&gadget->dev, req->buf, req->length,
> > +				direction ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
> > +
> > +		if (dma_mapping_error(&gadget->dev, req->dma)) {
> > +			dev_err(&gadget->dev, "failed to map buffer\n");
> > +			return -EFAULT;
> > +		}
> > +	}
> > +
> > +	return 0;
> 
> You forgot to set req->mapped.

actually there's no 'mapped' field on struct usb_request. That's a
nonsense added to all struct my_controller_request just because of that
DMA_ADDR_INVALID hackery. I'm dropping that completely. There were no
gadget drivers allocating memory from coherent or mapping requests
themselves, so req->mapped becomes useless.

-- 
balbi

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