lkml.org 
[lkml]   [2011]   [Apr]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH 1/2] usb: gadget: composite: Allow function drivers to defer setup responses
Date
From
On Tue, 19 Apr 2011 15:33:52 +0200, Roger Quadros  
<roger.quadros@nokia.com> wrote:
> @@ -895,6 +904,14 @@ composite_setup(struct usb_gadget *gadget, const
> struct usb_ctrlrequest *ctrl)
> if (w_value && !f->set_alt)
> break;
> value = f->set_alt(f, w_index, w_value);
> + if (value == USB_GADGET_DELAYED_STATUS) {
> + DBG(cdev,
> + "%s: interface %d (%s) requested delayed status\n",
> + __func__, intf, f->name);
> + cdev->delayed_status++;

Do we need it to be a counter? Won't simple flag do?

> + DBG(cdev, "delayed_status count %d\n",
> + cdev->delayed_status);
> + }
> break;
> case USB_REQ_GET_INTERFACE:
> if (ctrl->bRequestType != (USB_DIR_IN|USB_RECIP_INTERFACE))

> @@ -1289,3 +1310,41 @@ void usb_composite_unregister(struct
> usb_composite_driver *driver)
> return;
> usb_gadget_unregister_driver(&composite_driver);
> }
> +
> +/**
> + * usb_composite_setup_continue() - Continue the delayed setup transfer
> + * @cdev: the composite device who's setup transfer was delayed
> + *
> + * This function must be called by the USB function driver to continue
> + * with the setup transfer's data/status phase in case it had requested
> to
> + * delay the status phase. A USB function's setup handler (e.g.
> set_alt())
> + * can request the composite framework to delay the setup request's
> status phase
> + * by returning USB_GADGET_DELAYED_STATUS.
> + */
> +void usb_composite_setup_continue(struct usb_composite_dev *cdev)
> +{
> + int value;
> + struct usb_request *req = cdev->req;
> + unsigned long flags;
> +
> + DBG(cdev, "%s\n", __func__);
> + spin_lock_irqsave(&cdev->lock, flags);
> +
> + if (cdev->delayed_status == 0) {
> + WARN(cdev, "%s: Unexpected call\n", __func__);
> +
> + } else if (--cdev->delayed_status == 0) {
> + DBG(cdev, "%s: Completing delayed status\n", __func__);
> + req->length = 0;
> + req->zero = 1;
> + value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
> + if (value < 0) {
> + DBG(cdev, "ep_queue --> %d\n", value);
> + req->status = 0;
> + composite_setup_complete(cdev->gadget->ep0, req);
> + }
> + }
> +
> + spin_unlock_irqrestore(&cdev->lock, flags);
> +}

It's just my opinion but I dislike how it looks almost identical to the end
of composite_setup. I would rather make it more general (take value as
argument for instance) and let composite_setup() call it.

> diff --git a/include/linux/usb/composite.h @@ -37,6 +37,15 @@
> #include <linux/usb/ch9.h>
> #include <linux/usb/gadget.h>
> +/*
> + * USB function drivers should return USB_GADGET_DELAYED_STATUS if they
> + * wish to delay the status phase of the setup transfer till they are
> + * ready. The composite framework will then delay the data/status phase
> + * of the setup transfer till all the function drivers that requested
> for
> + * USB_GADGET_DELAYED_STAUS, invoke usb_composite_setup_continue().
> + *
> + */
> +#define USB_GADGET_DELAYED_STATUS 0x7fff /* Impossibly large
> value */

I was wondering if we could change it to something like EDELAYED and put
it to
<include/linux/errno.h>. Just thinking, it may be a bad idea.

--
Best regards, _ _
.o. | Liege of Serenely Enlightened Majesty of o' \,=./ `o
..o | Computer Science, Michal "mina86" Nazarewicz (o o)
ooo +-----<email/xmpp: mnazarewicz@google.com>-----ooO--(_)--Ooo--


\
 
 \ /
  Last update: 2011-04-19 16:25    [W:0.098 / U:0.028 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site