Re: [PATCH v8 00/26] Ingenic TCU patchset v8

[Paul Cercueil]

Hi,

On Fri, Jan 25, 2019 at 5:21 AM, Mathieu Malaterre <malat@xxxxxxxxxx> 
wrote:
> Paul,
>
> On Thu, Jan 24, 2019 at 10:41 PM Paul Cercueil <paul@xxxxxxxxxxxxxxx 
> <mailto:paul@xxxxxxxxxxxxxxx>> wrote:
> >  Hi Mathieu,
> >
> >  Le jeu. 24 janv. 2019 à 18:26, Mathieu Malaterre <malat@xxxxxxxxxx 
> > <mailto:malat@xxxxxxxxxx>> a
> >  écrit :
> >  > Paul,
> >  >
> >  > On Wed, Dec 12, 2018 at 11:09 PM Paul Cercueil 
> > <paul@xxxxxxxxxxxxxxx <mailto:paul@xxxxxxxxxxxxxxx>>
> >  > wrote:
> >  >>
> >  >>  Hi,
> >  >>
> >  >>  Here's the version 8 and hopefully final version of my patchset,
> >  >> which
> >  >>  adds support for the Timer/Counter Unit found in JZ47xx SoCs 
> > from
> >  >>  Ingenic.
> >  >
> >  > I can no longer boot my MIPS Creator CI20 with this series (merged
> >  > opendingux/for-upstream-timer-v8).
> >  >
> >  > Using screen+ttyUSB, I can see messages stopping at:
> >  >
> >  > ...
> >  > [  OK  ] Started Cgroup management daemon.
> >  >          Starting Regular background program processing daemon...
> >  > [  OK  ] Started Regular background program processing daemon.
> >  >          Starting System Logging Service...
> >  >          Starting Provide limited super user privileges to 
> > specific
> >  > users...
> >  >          Starting Restore /etc/resolv.conf if the system cras...s
> >  > shut down....
> >  >          Starting WPA supplicant...
> >  >          Starting D-Bus System Message Bus...
> >  > [  OK  ] Started D-Bus System Message Bus.
> >  >
> >  > Nothing really stands out in the error messages. Could you suggest
> >  > things to try out to get into a bootable state ?
> >
> >  I'm debugging it right now on jz4740, it seems to happen when the
> >  clocksource
> >  from the ingenic-timer driver is used. Is it your case? It should 
> > not
> >  happen
> >  if you have CONFIG_INGENIC_OST set.
>
> Here is what I see:
>
> $ grep CONFIG_INGENIC_OST arch/mips/configs/ci20_defconfig
> CONFIG_INGENIC_OST=y
> $ make O=ci20 ARCH=mips CROSS_COMPILE=mipsel-linux-gnu- ci20_defconfig
> $ grep CONFIG_INGENIC_OST ci20/.config
> CONFIG_INGENIC_OST=y
>
> The setting is coming from your commit:
>
> 8f66e6b9c98f MIPS: CI20: defconfig: enable OST driver
>
> In an attempt to solve the symptoms I even played with the clock rates
> with no success:
>
> &tcu {
> /* 3 MHz for the system timer and clocksource */
> assigned-clocks = <&tcu TCU_CLK_TIMER0>, <&tcu TCU_CLK_TIMER1>;
> assigned-clock-rates = <750000>, <750000>;
> };

This driver didn't see any big change since v6, and we're at v9 now.
I swear it worked fine before, I think even Paul Burton tested it and
reported it working fine. What kernel are you testing on? Could you try
on top of an older kernel, e.g. 4.18?

> >  >>  The big change is that the timer driver has been simplified. The
> >  >> code to
> >  >>  dynamically update the system timer or clocksource to a new 
> > channel
> >  >> has
> >  >>  been removed. Now, the system timer and clocksource are 
> > provided as
> >  >>  children nodes in the devicetree, and the TCU channel to use for
> >  >> these
> >  >>  is deduced from their respective memory resource. The PWM driver
> >  >> will
> >  >>  also deduce from its memory resources whether a given PWM 
> > channel
> >  >> can be
> >  >>  used, or is reserved for the system timers.
> >  >>
> >  >>  Kind regards,
> >  >>  - Paul Cercueil
> >  >>