Messages in this thread | | | Date | Sun, 21 Mar 2010 21:35:09 -0700 | From | Dmitry Torokhov <> | Subject | Re: [PATCH v2 1/6] hid: new driver for PicoLCD device |
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On Sun, Mar 21, 2010 at 05:37:37PM +0100, Bruno Prémont wrote: > On Sat, 20 March 2010 Dmitry Torokhov <dmitry.torokhov@gmail.com> wrote: > > > + usbhid_submit_report(data->hdev, report, USB_DIR_OUT); > > > + complete_all(&data->ready); > > > + INIT_COMPLETION(data->ready); > > > > Umm, what does this do, exactly? > > It wakes up anyone waiting on the completion and then resets the completion > as otherwise any future attempt to wait on it would succeed immediately. >
You realize that if you re-initialize the completion right after signalling it there is a big chance the waiters will miss it (they do check completion->done flags that you reset right away.
In general completions are suited for something that happens once (a single request - allocated - processed - signalled) but not for repeating use.
Thanks.
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