RE: [PATCH 00/11] OMAP3 CPUidle patches

[Kalle Jokiniemi <ext-kalle.jokiniemi@nokia.com>]

On pe, 2008-07-04 at 15:15 +0530, ext Rajendra Nayak wrote:
...
> > ext Högander Jouni <jouni.hogander@nokia.com> writes:

...

> > 
> > So Rajendra sent his uImage and it works quite ok what comes to off
> > mode on my sdp board. I still see problems with serial console (slow)
> > and on boot I need to generate manually interrupts to get it to
> > boot. Otherwise board hangs at this point:
> 
> Yes, I noticed this as well. It takes quite long to bootup if you don't 
> generate UART interrupts.
> After bootup once RET/OFF is hit, it takes a few hits to come out of it
> as IO wakeup is missing.

Jouni had a theory that the ethernet device could cause this slowness
trouble in the startup, so I investigated the matter a little further.
By enabling the debug prints in the ethernet chip driver,

diff --git a/drivers/net/smc91x.c b/drivers/net/smc91x.c
index 776c81d..7d1eead 100644
--- a/drivers/net/smc91x.c
+++ b/drivers/net/smc91x.c
@@ -62,7 +62,7 @@ static const char version[] =
 
 /* Debugging level */
 #ifndef SMC_DEBUG
-#define SMC_DEBUG              0
+#define SMC_DEBUG              1
 #endif


I was able to see, that we get lots of RX overrun interrupts with
cpu_idle, meaning that incoming stuff is not getting processed. By
generating UART interrupts, I we probably can also catch more network RX
interrupts and this helps the bootup go faster. With cpu_idle disabled,
there were no RX overruns.

I'll try to see if this can be fixed somehow.

> 
> > 
> > eth0: link up
> > Sending DHCP requests ., OK
> > IP-Config: Got DHCP answer from 0.0.0.0, my address is 192.168.2.101
> > IP-Config: Complete:
> >      device=eth0, addr=192.168.2.101, mask=255.255.255.0, 
> > gw=192.168.2.1,
> >      host=192.168.2.101, domain=ntc.nokia.com, nis-domain=(none),
> >      bootserver=0.0.0.0, rootserver=172.22.146.197, rootpath=
> > Looking up port of RPC 100003/2 on 172.22.146.197
> > Looking up port of RPC 100005/1 on 172.22.146.197
> > VFS: Mounted root (nfs filesystem).
> > Freeing init memory: 108K
> > 
> > Rajendra, are you still using .config file you sent to me? Are all the
> > changes in your tree available in l-o list.
> 
> Yes, all the changes are part of the 11 patch set + 1 rework fixes patch I sent.
> To debug further, can you put a few prints in omap3_enter_idle and omap3_enter_idle_bm
> to see what states are selected by the menu gov. 
> We will then know if CORE RET/OFF is attempted but not achieved due to some reason, or 
> never attempted altogether.

My setup does not seem to go beyond C2 state, btw. So I'll need to debug
that also a bit. The above-mentioned patches are applied.

Br, Kalle


...

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