Hi Dave,<br><br>Thanks for your reply.<br><br><div class="gmail_quote">On Wed, Apr 18, 2012 at 1:01 PM, Dave Hylands <span dir="ltr"><<a href="mailto:dhylands@gmail.com">dhylands@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0pt 0pt 0pt 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
Hi Arun,<br>
<div class="im"><br>
On Tue, Apr 17, 2012 at 11:44 PM, Arun KS <<a href="mailto:getarunks@gmail.com">getarunks@gmail.com</a>> wrote:<br>
><br>
> Hello Guys,<br>
><br>
> System is working normal after this BUG.<br>
> PC is at 0x400b4614, probably a mmaped address.<br>
><br>
> Just wondering how can this BUG happen when a process is running in user<br>
> space.<br>
><br>
> Can it be something like this<br>
> 1) enter to kernel from userspace through some system call.<br>
> 2) kernel disables the interrupt and return to user space.<br>
<br>
</div>Don't do that<br></blockquote><div><br>I don't do that. This scenario mentioned is a just a wild guess.<br></div><blockquote class="gmail_quote" style="margin:0pt 0pt 0pt 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div class="im"><br>
> 3) and now it can happen in user space?<br>
<br>
</div>Because something in userspace made a blocking call which would cause<br>
a context switch to occur and your driver erroneously left interrupts<br>
disabled.<br></blockquote><div>In that case, my system should have been unstable afterwards if interrupts are left disabled. But that is not happening. <br><br>If we return to user space with interrupts disabled, can we switch back again to kernel using a system cal(because interrupts are already disabled)?<br>
<br>Arun<br><br></div><div></div><blockquote class="gmail_quote" style="margin:0pt 0pt 0pt 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<span class="HOEnZb"><font color="#888888"><br>
--<br>
Dave Hylands<br>
Shuswap, BC, Canada<br>
<a href="http://www.davehylands.com" target="_blank">http://www.davehylands.com</a><br>
</font></span></blockquote></div><br>