3.3-rc1 console lag (was: Re: [PATCH v8 00/20] OMAP2+: UART: Runtime adaptation + cleanup)

3.3-rc1 console lag (was: Re: [PATCH v8 00/20] OMAP2+: UART: Runtime adaptation + cleanup)

[Ramirez Luna, Omar]

Hi,

On Fri, Nov 11, 2011 at 3:57 AM, Govindraj.R <govindraj.raja@ti.com> wrote:
> Converting uart driver to adapt to pm runtime API's.
> Code re-org + cleanup.
> Moving some functionality from serial.c to omap-serial.c
...
>
> Ensure CONFIG_OMAP_PRM is set while testing irq_chaining with uart.
> And for pm_qos usage ensure CONFIG_CPU_IDLE is selected other wise
> console might be sluggish.

There is console lag for omap2plus_defconfig given that
CONFIG_CPU_IDLE is not enabled. Is the intention to force CPU_IDLE
into the defconfig or find an alternative for the new pm_qos when cpu
idle is disabled.

Seen on beagle-xm and 3.3-rc1.

Regards,

Omar

Re: 3.3-rc1 console lag (was: Re: [PATCH v8 00/20] OMAP2+: UART: Runtime adaptation + cleanup)

[Paul Walmsley]

On Wed, 25 Jan 2012, Ramirez Luna, Omar wrote:

> Hi,
> 
> On Fri, Nov 11, 2011 at 3:57 AM, Govindraj.R <govindraj.raja@ti.com> wrote:
> > Converting uart driver to adapt to pm runtime API's.
> > Code re-org + cleanup.
> > Moving some functionality from serial.c to omap-serial.c
> ...
> >
> > Ensure CONFIG_OMAP_PRM is set while testing irq_chaining with uart.
> > And for pm_qos usage ensure CONFIG_CPU_IDLE is selected other wise
> > console might be sluggish.
> 
> There is console lag for omap2plus_defconfig given that
> CONFIG_CPU_IDLE is not enabled. Is the intention to force CPU_IDLE
> into the defconfig or find an alternative for the new pm_qos when cpu
> idle is disabled.
> 
> Seen on beagle-xm and 3.3-rc1.

Try this

http://marc.info/?l=linux-arm-kernel&m=132754676814391&w=2


- Paul

Re: 3.3-rc1 console lag (was: Re: [PATCH v8 00/20] OMAP2+: UART: Runtime adaptation + cleanup)

[Ramirez Luna, Omar]

Hi Paul,

On Wed, Jan 25, 2012 at 9:00 PM, Paul Walmsley <paul@pwsan.com> wrote:
...
>> > Ensure CONFIG_OMAP_PRM is set while testing irq_chaining with uart.
>> > And for pm_qos usage ensure CONFIG_CPU_IDLE is selected other wise
>> > console might be sluggish.
>>
>> There is console lag for omap2plus_defconfig given that
>> CONFIG_CPU_IDLE is not enabled. Is the intention to force CPU_IDLE
>> into the defconfig or find an alternative for the new pm_qos when cpu
>> idle is disabled.
>>
>> Seen on beagle-xm and 3.3-rc1.
>
> Try this
>
> http://marc.info/?l=linux-arm-kernel&m=132754676814391&w=2

I tried the series and the console returned to normal, I can confirm
that the following patch helps:

tty: serial: OMAP: use a 1-byte RX FIFO threshold in PIO mode

Thanks,

Omar