On Mon, Jul 25, 2011 at 1:48 AM, Palash Bandyopadhyay
<palash.bandyopadh...@conexant.com> wrote:
> Mauro/Devin,
>
>  Can someone give steps to reproduce the problem? Also if we need any 
> particular h/w board to reproduce this problem. I dont seem to recall any 
> delay requirement on the chip at power up/cycle time. Any I also dont recall 
> seeing any problems with the Conexant evk boards. Mauro, have you been able 
> to see this issue with a Conexant board?

Hello Palash,

The problem occurs if the kernel is configured for CONFIG_HZ to 1000
and on the Hauppauge USBLIve 2 hardware design.  I'm assuming it's
tied to two factors:

1.  Some aspect of the power supply tied to the Mako core being a
little slow to startup.  I haven't compared the schematic to the EVK,
but I could do that if we *really* think that is a worthwhile
exercise.
2.  On typical kernels which have CONFIG_HZ set to 100, a call to
msleep(5) will actually take approximately 10ms (due to the clock
resolution).  However, if you have CONFIG_HZ set to 1000 then the call
*actually* takes 5ms which is too short for this design.  In other
words, you would be unlikely to notice the issue unless you had
CONFIG_HZ set to a high enough resolution for the msleep(5) to
actually take 5ms.

The changed as proposed should be very low impact.  For users who have
CONFIG_HZ set to 100 (which is typical), there will be no visible
increase in time (since the call was already taking 10ms).  For users
who have CONFIG_HZ set to 1000, the net effect is that it takes an
extra 20ms to switch hardware modes (since the #define in question is
used at most four times in sequence).

Devin

-- 
Devin J. Heitmueller - Kernel Labs
http://www.kernellabs.com
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