Re: [PATCH 1/1] media: dvb-usb/af9015, fix disconnection crashes

[Dmitry Torokhov]

On Thu, Feb 04, 2010 at 07:33:22PM +0100, Jiri Slaby wrote:
> On 02/04/2010 07:14 PM, Dmitry Torokhov wrote:
> > On Thu, Feb 04, 2010 at 11:31:45AM +0100, Jiri Slaby wrote:
> >  +
> >> +static int dvb_event(struct hid_device *hdev, struct hid_field *field,
> >> +		struct hid_usage *usage, __s32 value)
> >> +{
> >> +	/* we won't get a "key up" event */
> >> +	if (value) {
> >> +		input_event(field->hidinput->input, usage->type, usage->code, 1);
> >> +		input_event(field->hidinput->input, usage->type, usage->code, 0);
> > 
> > Do not ever forget input_sync(), you need 2 of them here.
> > 
> > With the latest changes to evdev, if you are using SIGIO you won't get
> > wioken up until EV_SYN/SYN_REPORT.
> 
> HID layer syncs on its own. So the second is not needed. Why is needed
> the first?
> 

Userpsace has a right to accumulate events and only act on them when
receiving EV_SYN. Press + release in the same event block may be treated
as no change. The same as REL_X +2, REL_X -2 - no need to move pointer at
all. And so on.

> I.e. should there be one also in dvb_usb_read_remote_control?

Probably, I have not looked.

-- 
Dmitry
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