Re: OMAP34xx

Víctor M. Jáquez L.
2012-02-07T22:50:00Z

On Tue, Feb 07, 2012 at 02:36:06PM -0800, Kevin Hilman wrote:
> Tony Lindgren <tony@atomide.com> writes:
>
> [...]
>
> >> > > --- a/arch/arm/mach-omap2/pm34xx.c
> >> > > +++ b/arch/arm/mach-omap2/pm34xx.c
> >> > > @@ -420,7 +420,7 @@ static void omap3_pm_idle(void)
> >> > > {
> >> > > local_fiq_disable();
> >> > >
> >> > > - if (omap_irq_pending())
> >> > > + if (omap_irq_pending() || 1)
> >> > > goto out;
> >> > >
> >> > > trace_power_start(POWER_CSTATE, 1, smp_processor_id());
> >> >
> >> > This does not look right to me. I thought reverting of the serial
> >> > patches should have already solved the issue you're seeing with
> >> > slow serial port?
> >> >
> >> > Those are the reverting commits drivers/tty/serial/serial-omap.c:
> >> >
> >> > 8a74e9ffd97dc9de063de8c02ae32db79dd60436 (Revert "tty: serial: OMAP: ensure
> >> > FIFO levels are set correctly in non-DMA mode")
> >> >
> >> > af681cad3f79ad8f7bd6cb170b70990aeef74233 (Revert "tty: serial: OMAP: transmit
> >> > FIFO threshold interrupts don't wake the chip")
> >>
> >> These commits have absolutely nothing to do with it. I pointed out the
> >> bad commit in one of my emails:
> >>
> >> commit 2fd149645eb46d26130d7070c6de037dddf34880
> >> Author: Govindraj.R <govindraj.raja@ti.com>
> >> Date: Wed Nov 9 17:41:21 2011 +0530
> >>
> >> ARM: OMAP2+: UART: Remove omap_uart_can_sleep and add pm_qos
> >>

[...]

> >>
> >> Basically, it looks like the OMAP 3 UART is not delivering transmit IRQs
> >> while in some of the deeper low power modes.
> >>
> >> I tried reverting the rest of the patches between this one and HEAD for
> >> omap-serial.c, but they have no effect what so ever on this bug. As I
> >> said in one of my emails in this thread, the above commit can't be
> >> trivially reverted because some other stuff that the code relied upon
> >> has vanished.
> >>
> >> So, the above along with the other part in arch/arm/mach-omap2/cpuidle34xx.c
> >> is the smallest 'fix' I could find if resolving the regression.
> >
> > OK, thanks, that should be enough info for let Kevin take a look at this.
>
> This one is indeed strange. I have not seen this on the 34xx devices
> I'm using (3430/n900, 3530/Overo, 3630/Zoom3).
>
> Just to confirm. I assume you are using v3.3-rc2 (or later Linus
> master) which has a few fixes for this driver already.

If it helps, I observed the same issue in a beagleboard rev B6, with v3.3-rc2

Russell's patch fixed it.

vmjl

>
> Also, is this happening on your LDP. Which ES revision does your 3430
> have?
>
> Kevin