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SubjectRe: [PATCH v3] usb: gadget: Add UDC driver for Aeroflex Gaisler GRUSBDC
Hi,

On Fri, Dec 13, 2013 at 08:48:30AM +0100, Andreas Larsson wrote:
> >On Wed, Dec 04, 2013 at 09:13:58AM +0100, Andreas Larsson wrote:
> >>+static void gr_finish_request(struct gr_ep *ep, struct gr_request *req,
> >>+ int status)
> >>+{
> >>+ struct gr_udc *dev;
> >>+
> >>+ list_del_init(&req->queue);
> >>+
> >>+ if (likely(req->req.status == -EINPROGRESS))
> >>+ req->req.status = status;
> >>+ else
> >>+ status = req->req.status;
> >>+
> >>+ dev = ep->dev;
> >>+ usb_gadget_unmap_request(&dev->gadget, &req->req, ep->is_in);
> >>+ gr_free_dma_desc_chain(dev, req);
> >>+
> >>+ if (ep->is_in) /* For OUT, actual gets updated bit by bit */
> >>+ req->req.actual = req->req.length;
> >>+
> >>+ if (!status) {
> >>+ if (ep->is_in)
> >>+ gr_dbgprint_request("SENT", ep, req);
> >>+ else
> >>+ gr_dbgprint_request("RECV", ep, req);
> >>+ }
> >>+
> >>+ /* Prevent changes to ep->queue during callback */
> >>+ ep->callback = 1;
> >>+ if (req == dev->ep0reqo && !status) {
> >>+ if (req->setup)
> >>+ gr_ep0_setup(dev, req);
> >>+ else
> >>+ dev_err(dev->dev,
> >>+ "Unexpected non setup packet on ep0in\n");
> >>+ } else if (req->req.complete) {
> >>+ unsigned long flags;
> >>+
> >>+ /*
> >>+ * Complete should be called with interrupts disabled according
> >>+ * to the contract of struct usb_request
> >>+ */
> >>+ local_irq_save(flags);
> >
> >sorry but this driver isn't ready for inclusion. local_irq_save() is a
> >pretty good hint that there's something wrong in the driver. Consider
> >the fact that local_irq_save() will disable preemption even when
> >CONFIG_PREEMPT_FULL is enabled and you have a bit a problem.
>
> This connection between local_irq_save and CONFIG_PREEMPT_RT_FULL was
> unknown to me. Sure, I can disable interrupts right at spin lock
> time.

that's better.

> >Also, the way you're using thread IRQs is quite wrong. I can't let that
> >pass and get merged upstream, sorry.
>
> What is quite wrong? What is it that I need to fix?

Ideally the hardirq handler should be usually to actually check if
$this_device generated the IRQ, that should involve reading a IRQSTATUS
register of some sort.

Sure, check that IRQs are actually enabled, but you also need to read
STATUS register before waking the thread up.

--
balbi
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