<div dir="ltr"><div>!! is generally used to make the return bool value.<br></div>You can use kernelnewbies and linux kernel mailing list.<br></div><div class="gmail_extra"><br><br><div class="gmail_quote">On Mon, Apr 1, 2013 at 12:43 PM, Ben Wu <span dir="ltr"><<a href="mailto:crayben@yahoo.cn" target="_blank">crayben@yahoo.cn</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><table border="0" cellpadding="0" cellspacing="0"><tbody><tr><td style="font:inherit" valign="top"><br><blockquote style="border-left:2px solid rgb(16,16,255);margin-left:5px;padding-left:5px">
<br><div><table border="0" cellpadding="0" cellspacing="0"><tbody><tr><td style="font:inherit" valign="top">Dear All：<br>1> I found some placeuse two "!!", what's means <br> if(button->gpio != INVALID_GPIO)<br>
state = !!((gpio_get_value(button->gpio) ? 1 : 0) ^ button->active_low);<br> else<br> state = !!button->adc_state;<br><br>2> is there some MSN group to study linux kernel or discuss it ?<br><br>
Thanks and Best Regards<br>
Ben Wu<br>
<a href="mailto:MSN%3Acrayben@yahoo.cn" target="_blank">MSN:crayben@yahoo.cn</a><br><br></td></tr></tbody></table></div></blockquote></td></tr></tbody></table><br>_______________________________________________<br>
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