Re: [PATCH v2]: Fix e500 v2 core reboot bug

[Zang Roy-r61911 <tie-fei.zang@freescale.com>]

On Wed, 2007-05-30 at 10:40, Kumar Gala wrote:
> On May 29, 2007, at 9:34 PM, Zang Roy-r61911 wrote:
> 
> > On Wed, 2007-05-30 at 03:29, Kumar Gala wrote:
> >> On May 28, 2007, at 9:36 PM, Zang Roy-r61911 wrote:
> >>
> >>> Fix the e500 v2 core reset bug.
> >>> For e500 v2 core, a new reset control register is added to
> >>> reset the core.
> >>> On 85xx CDS board with e500 v2 core, normal reboot code will
> >>> induce DDR block in u-boot. This patch fixes this bug. It is
> >>> also tested on legacy e500 v1 core.
> >>
> >> what happens on an e500 based 85xx system?
> >
> > Without this patch on MPC8548CDS board, after key in "reboot"
> command,
> > the u-boot will hang at DDR init. See the following log without this
> > patch:
> 
> Sorry I meant what happens on a e500 v1 based 85xx system w/this
> patch.

E500 V1 core can boot up normally with/without this patch. Such as
8555CDS system.

> 
> - k
> 
> >
> > --- log start ---
> > ~ # uname -a
> > Linux mpc8548cds 2.6.22-rc2-g843b8c89-dirty #5 Tue May 29 16:37:21
> CST
> > 2007 ppc
> > unknown
> > ~ # reboot
> > ~ # Stopping the boa webserver:
> > Stopping the port mapper:
> > Stopping inetd:
> > Syncing hardware clock to system time
> > hwclock: Could not set the RTC time: Invalid argument
> > Unmounting filesystems
> > umount: Cannot open /proc/mounts
> > The system is going down NOW !!
> > Sending SIGTERM to all processes.
> > Please stand by while rebooting the system.
> > Restarting system.
> >
> >
> > U-Boot 1.1.6-gcd32691c-dirty (Apr  2 2007 - 17:42:01)
> >
> > CPU:   8548_E, Version: 2.0, (0x80390020)
> > Core:  E500, Version: 2.0, (0x80210020)
> > Clock Configuration:
> >        CPU: 990 MHz, CCB: 396 MHz,
> >        DDR: 198 MHz, LBC:  49 MHz
> > L1:    D-cache 32 kB enabled
> >        I-cache 32 kB enabled
> > Board: CDS Version 0x13, PCI Slot 1
> > CPU Board Revision 114.121 (0x7279)
> >     PCI1: 32 bit, 33 MHz, async
> >     PCI2: disabled
> > I2C:   ready
> > DRAM:  Initializing
> >     SDRAM: 64 MB
> >     DDR: 256 MB
> >
> > --- log end --
> >
> > This patch has been tested on 8548/55 CDS board and 8540/60 ADS
> board.
> >
> >> I'm not terrible happy with blindly writing to rstcr.
> >>
> > I can understand you.
> > But I jut want to make things simple and workable.
> > Any idea?
> 
> one idea would be for us to add a property on the soc node.   
> Something like has-rstcr or something similar in a guts node?
I have seen your suggestion before to add a property in device tree.
But I still think the current implementation is simple.
Anyway, I can try your suggestion.
Thanks.
Roy