[PATCH] usb: fsl_udc_core: fix build breakage when building for ARM arch
eric.y.miao at gmail.com
Fri Jun 24 05:58:12 EDT 2011
On Fri, Jun 24, 2011 at 5:56 PM, Russell King - ARM Linux
<linux at arm.linux.org.uk> wrote:
> On Fri, Jun 24, 2011 at 02:03:08AM +0200, Anatolij Gustschin wrote:
>> Commit 09ba0def introduced build breakage on ARM arch.
>> Fix it by setting accessors using a static inline function
>> which is a nop when compiling the driver for ARM arch.
>> Don't use flush_dcache_range(), convert to the DMA API
>> usage instead. USB2.0CV Halt Endpoint Test succeeds on
>> PPC. Tested both on ARM i.MX31 and mpc5121 PPC.
> While this may work, if you enable DMA API debugging, you'll get
> complaints. Please test your changes on ARM with CONFIG_DMA_API_DEBUG
> /* FIXME: fsl_alloc_request() ignores ep argument */
> udc->status_req = container_of(fsl_alloc_request(NULL, GFP_KERNEL),
> struct fsl_req, req);
> /* allocate a small amount of memory to get valid address */
> udc->status_req->req.buf = kmalloc(8, GFP_KERNEL);
> udc->status_req->req.dma = virt_to_phys(udc->status_req->req.buf);
> /* Borrow the per device status_req */
> req = udc->status_req;
> /* Fill in the reqest structure */
> *((u16 *) req->req.buf) = cpu_to_le16(tmp);
> /* flush cache for the req buffer */
> flush_dcache_range((u32)req->req.buf, (u32)req->req.buf + 8);
> req->ep = ep;
> req->req.length = 2;
> req->req.status = -EINPROGRESS;
> req->req.actual = 0;
> req->req.complete = NULL;
> req->dtd_count = 0;
> /* prime the data phase */
> if ((fsl_req_to_dtd(req) == 0))
> fsl_queue_td(ep, req);
> I've no idea why this driver can't use dma_map_single() before queuing,
> and dma_unmap_single() once the req is complete. It looks like done()
> will do the unmap provided we map it correctly and set req->mapped.
> So, I think that virt_to_phys can be killed, and a dma_map_single() can
> be done in place of the flush_dcache_range to set req->req.dma, and
> req->mapped needs to be set to cause it to be unmapped.
It looks like it's using dma_* API for endpoints other than ep0.
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