Re: pq2_find_bridges hangs system

Re: pq2_find_bridges hangs system

[Vitaly Bordug]

Alex BASTOS wrote:
> Hi,
> 
> I am working on a board with a MPC8248 based on ADS8272.
> Until now I was working with ppc kernel 2.6.11. Now, it's
> time to go up, so I am trying 2.6.15-rc2.
> 
> Unfortunately, kernel hangs at boot-up, and with a BDI2000
> I have reached the pq2_find_bridges() call, more precisely,
> in indirect_read_config(). Now I am a bit lost, as I have
> almos any knowledge about PCI.
> 
> The board doesn't need PCI support at all, but I need it
> active on kernel as it is required by USB HCD stack.
> 
> I have tested this on the ADS8272 and i doesn't happends,
> so, any clue.
> 
> And, has the indirect_read_config any to do with the PCI9
> workaround, which is supposed to be corrected on HIP7
> devices?
> 
There are 2 indirect_read_config(), one for PCI9 case, and one for not. 
I guess you should have CONFIG_8260_PCI9 disabled.

If config seems OK, pleas submit backtrace. As long as I can see, "proper" setup_indirect_pci has been moved over to arch/powerpc/sysdev/indirect_pci.c.
Check it it is compiled/used.

> Thanks in advance.
> 
> Alex BASTOS
> _______________________________________________
> Linuxppc-embedded mailing list
> Linuxppc-embedded@ozlabs.org
> https://ozlabs.org/mailman/listinfo/linuxppc-embedded
> 
> 


-- 
Sincerely, 
Vitaly

pq2_find_bridges hangs system

[Alex BASTOS]

Hi,

I am working on a board with a MPC8248 based on ADS8272.
Until now I was working with ppc kernel 2.6.11. Now, it's
time to go up, so I am trying 2.6.15-rc2.

Unfortunately, kernel hangs at boot-up, and with a BDI2000
I have reached the pq2_find_bridges() call, more precisely,
in indirect_read_config(). Now I am a bit lost, as I have
almos any knowledge about PCI.

The board doesn't need PCI support at all, but I need it
active on kernel as it is required by USB HCD stack.

I have tested this on the ADS8272 and i doesn't happends,
so, any clue.

And, has the indirect_read_config any to do with the PCI9
workaround, which is supposed to be corrected on HIP7
devices?

Thanks in advance.

Alex BASTOS

Re: pq2_find_bridges hangs system

[Alex BASTOS]

Vitaly,

> >
> There are 2 indirect_read_config(), one for PCI9 case, and one for not.
> I guess you should have CONFIG_8260_PCI9 disabled.
>
> If config seems OK, pleas submit backtrace. As long as I can see, "proper"
> setup_indirect_pci has been moved over to arch/powerpc/sysdev/indirect_pci.c.
> Check it it is compiled/used.
>

Config file seems OK to me:

# CONFIG_CPCI690 is not set
CONFIG_PPC_INDIRECT_PCI=y
CONFIG_PCI=y
CONFIG_PCI_DOMAINS=y
CONFIG_PCI_8260=y
# CONFIG_PCI_LEGACY_PROC is not set
# CONFIG_PCI_DEBUG is not set
# CONFIG_NET_PCI is not set

and indirect_pci from arch/powerpc is compiled and used ...

I have tested a bit more. The call trace would be:

[c01db170] m8260_setup_arch
[c01db87c] pq2_find_bridges
[c01dbfa0] pciauto_bus_scan
[c000a754] early_read_config_byte
[c00c8f54] pci_bus_read_config_byte
[c0011424] indirect_read_config

I have done manually, since GDB only reports last two,
and I couldn't get it from log_buf.

(gdb) bt
#0  indirect_read_config (bus=0x0, devfn=3223241436,
                          offset=8, len=14, val=0x1032)
    at arch/powerpc/sysdev/indirect_pci.c:32

#1  0xc00c8fb4 in pci_bus_read_config_byte (bus=0xc01ec2dc,
                       devfn=8, pos=14, value=0xc01d1f3a "")
    at drivers/pci/access.c:52

Now I have check indirect_read_config, and I have seen
the call ends itself, but after that it returns to

   pci_bus_read_config_dword

executes some asm and then hangs.

Any idea?

Thanks,

Alex BASTOS

Re: pq2_find_bridges hangs system

[Kalle Pokki]

Alex BASTOS wrote:

>The Tranfer Error makes not many sense for me, as _TEA is pulled-up.
>Maybe the oops after that is caused by the bad call return point?
>  
>
I remember using this to prevent machine check exceptions during the PCI 
scan. This is in the beginning of the pciauto_bus_scan() function.

--- trunk/linux/arch/ppc/syslib/pci_auto.c	(revision 127)
+++ trunk/linux/arch/ppc/syslib/pci_auto.c	(revision 128)
@@ -382,6 +382,10 @@
 	unsigned short vid;
 	unsigned char header_type;
 
+
+	/* must ignore machine checks during scan */
+	*(volatile unsigned short *) 0xf0010888 &= ~0x0800;
+
 	/*
 	 * Fetch our I/O and memory space upper boundaries used
 	 * to allocated base addresses on this hose.

Re: pq2_find_bridges hangs system

[Alex BASTOS]

Vitally,

Finally, more clever informacion from log_buf.
(...and sorry about previos uncomplete information)

<5>Linux version 2.6.15-rc2 (alebas@xxxx) (gcc version 3.3.2) #1 PREEMPT Fri Dec
2 12:22:09 CET 2005
<6>Televes xxxxxx
<4>arch/ppc/syslib/m82xx_pci.c: The PCI bus is 66666666 Mhz.
<4>Waiting 1 second after deasserting RST...
<4>Machine check in kernel mode.
<4>Caused by (from SRR1=41030): Transfer error ack signal
<4>Oops: machine check, sig: 7 [#1]
<4>PREEMPT
<4>NIP: C001150C LR: C0011530 SP: C01D1EA0 REGS: c01d1df0 TRAP: 0200    Not
tainted
<4>MSR: 00041030 EE: 0 PR: 0 FP: 0 ME: 1 IR/DR: 11
<4>TASK = c01a2ff8[0] 'swapper' THREAD: c01d0000
<4>Last syscall: 0
<6>GPR00: 000000FF C01D1EA0 C01A2FF8 00000000 00000008 F0010906 00000001
C01D1ED8
<6>GPR08: 00000001 00000002 00000800 F0010904 24008028 FFFFFFFF 03FFE000
00000000
<6>GPR16: 00000001 00000001 FFFFFFFF 007FFF00 03FF8CE8 00000000 00000003
03BCB578
<6>GPR24: 00000000 00000000 00000001 0000000E 00000008 C01D1ED8 C01EC2DC
C01FC000
<4>NIP [c001150c] indirect_read_config+0xe8/0x11c
<4>LR [c0011530] indirect_read_config+0x10c/0x11c
<4>Call trace:
<4> [c00c8fb4] pci_bus_read_config_byte+0x60/0xa8
<4> [c000a784] early_read_config_byte+0x30/0x44
<4> [c01dc04c] pciauto_bus_scan+0xac/0x298
<4> [c01dba00] pq2_find_bridges+0x184/0x1b0
<4> [c01db1a0] m8260_setup_arch+0x30/0x80
<4> [c01d8c2c] setup_arch+0x110/0x18c
<4> [c01d2544] start_kernel+0x34/0x1bc
<4> [000032bc] 0x32bc
<4>Oops: kernel access of bad area, sig: 11 [#2]
<4>PREEMPT
<4>NIP: C001196C LR: C0012940 SP: C01D1C70 REGS: c01d1bc0 TRAP: 0300    Not
tainted
<4>MSR: 00001032 EE: 0 PR: 0 FP: 0 ME: 1 IR/DR: 11
<4>DAR: 00000000, DSISR: 20000000
<4>TASK = c01a2ff8[0] 'swapper' THREAD: c01d0000
<4>Last syscall: 0
<6>GPR00: 00010005 C01D1C70 C01A2FF8 C01A2FF8 00000000 00000001 C01ED8E0
00000000
<6>GPR08: 00000000 00000001 00000078 C01D0000 00000000 FFFFFFFF 03FFE000
00000000
<6>GPR16: 00000001 00000001 FFFFFFFF 007FFF00 03FF8CE8 00000000 00000003
C01F0000
<6>GPR24: C01F0000 00000000 00000001 0000000E C01EB09C 00000000 C01EDD20
C01A2FF8
<4>NIP [c001196c] dequeue_task+0x0/0x78
<4>LR [c0012940] scheduler_tick+0x244/0x3b0
<4>Call trace:
<4> [c002284c] update_process_times+0xa4/0x168
<4> [c0005bb4] timer_interrupt+0x90/0x25c
<4> [c0004a7c] ret_from_except+0x0/0x14
<4> [c0004d9c] die+0xa0/0xc4
<4> [c0004a30] ret_from_except_full+0x0/0x4c
<4> [c001150c] indirect_read_config+0xe8/0x11c
<4> [c00c8fb4] pci_bus_read_config_byte+0x60/0xa8
<4> [c000a784] early_read_config_byte+0x30/0x44
<4> [c01dc04c] pciauto_bus_scan+0xac/0x298
<4> [c01dba00] pq2_find_bridges+0x184/0x1b0
<4> [c01db1a0] m8260_setup_arch+0x30/0x80
<4> [c01d8c2c] setup_arch+0x110/0x18c
<4> [c01d2544] start_kernel+0x34/0x1bc
<4> [000032bc] 0x32bc
<0>Kernel panic - not syncing: Aiee, killing interrupt handler!
<4> <0>Rebooting in 180 seconds..

The Tranfer Error makes not many sense for me, as _TEA is pulled-up.
Maybe the oops after that is caused by the bad call return point?

Thanks,

Alex BASTOS

Re: pq2_find_bridges hangs system

[Vitaly Bordug]

Alex, 
please probe this. If it will not help, pq2ads_setup_pci should be digged for some board specifics.

Also, check if hose->set_cfg_type is 1 as done for ads8272.

-------- Original Message --------
Subject: [patch 01/34] ppc32: Fix incorrect PCI frequency value
Date: Thu, 01 Dec 2005 00:51:15 -0800
From: akpm@osdl.org
To: torvalds@osdl.org
CC: akpm@osdl.org, vbordug@ru.mvista.com, galak@kernel.crashing.org


From: Vitaly Bordug <vbordug@ru.mvista.com>

The time to wait after deasserting PCI_RST has been counted with incorrect
value - this patch fixes the issue.

Signed-off-by: Vitaly Bordug <vbordug@ru.mvista.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---

 arch/ppc/syslib/m82xx_pci.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletion(-)

diff -puN arch/ppc/syslib/m82xx_pci.c~ppc32-fix-incorrect-pci-frequency-value arch/ppc/syslib/m82xx_pci.c
--- devel/arch/ppc/syslib/m82xx_pci.c~ppc32-fix-incorrect-pci-frequency-value	2005-11-30 23:58:00.000000000 -0800
+++ devel-akpm/arch/ppc/syslib/m82xx_pci.c	2005-11-30 23:58:00.000000000 -0800
@@ -248,7 +248,8 @@ pq2ads_setup_pci(struct pci_controller *
 	pci_div = ( (sccr & SCCR_PCI_MODCK) ? 2 : 1) *
 			( ( (sccr & SCCR_PCIDF_MSK) >> SCCR_PCIDF_SHIFT) + 1);
 	freq = (uint)((2*binfo->bi_cpmfreq)/(pci_div));
-	time = (int)666666/freq;
+	time = (int)66666666/freq;
+
 	/* due to PCI Local Bus spec, some devices needs to wait such a long
 	time after RST 	deassertion. More specifically, 0.508s for 66MHz & twice more for 33 */
 	printk("%s: The PCI bus is %d Mhz.\nWaiting %s after deasserting RST...\n",__FILE__,freq,
_



-- 
Sincerely, 
Vitaly

Re: pq2_find_bridges hangs system

[Alex BASTOS]

Vitaly,


> Alex,
> please probe this. If it will not help, pq2ads_setup_pci should be digged for
> some board specifics.
>

I'll give it a try. Unfortunately (or fortunately), i won't be in the lab for
a week (i am on holidays). I will comment you then.


> Also, check if hose->set_cfg_type is 1 as done for ads8272.
>
Yes, it is.


Best regards,

Alex


> -------- Original Message --------
> Subject: [patch 01/34] ppc32: Fix incorrect PCI frequency value
> Date: Thu, 01 Dec 2005 00:51:15 -0800
> From: akpm@osdl.org
> To: torvalds@osdl.org
> CC: akpm@osdl.org, vbordug@ru.mvista.com, galak@kernel.crashing.org
>
>
> From: Vitaly Bordug <vbordug@ru.mvista.com>
>
> The time to wait after deasserting PCI_RST has been counted with incorrect
> value - this patch fixes the issue.
>
> Signed-off-by: Vitaly Bordug <vbordug@ru.mvista.com>
> Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
> Signed-off-by: Andrew Morton <akpm@osdl.org>
> ---
>
>  arch/ppc/syslib/m82xx_pci.c |    3 ++-
>  1 files changed, 2 insertions(+), 1 deletion(-)
>
> diff -puN arch/ppc/syslib/m82xx_pci.c~ppc32-fix-incorrect-pci-frequency-value
> arch/ppc/syslib/m82xx_pci.c
> ---
>
devel/arch/ppc/syslib/m82xx_pci.c~ppc32-fix-incorrect-pci-frequency-value	2005-11-30
> 23:58:00.000000000 -0800
> +++ devel-akpm/arch/ppc/syslib/m82xx_pci.c	2005-11-30 23:58:00.000000000
> -0800
> @@ -248,7 +248,8 @@ pq2ads_setup_pci(struct pci_controller *
>  	pci_div = ( (sccr & SCCR_PCI_MODCK) ? 2 : 1) *
>  			( ( (sccr & SCCR_PCIDF_MSK) >> SCCR_PCIDF_SHIFT) + 1);
>  	freq = (uint)((2*binfo->bi_cpmfreq)/(pci_div));
> -	time = (int)666666/freq;
> +	time = (int)66666666/freq;
> +
>  	/* due to PCI Local Bus spec, some devices needs to wait such a long
>  	time after RST 	deassertion. More specifically, 0.508s for 66MHz & twice
> more for 33 */
>  	printk("%s: The PCI bus is %d Mhz.\nWaiting %s after deasserting
> RST...\n",__FILE__,freq,
> _
>
>
>
> --
> Sincerely,
> Vitaly
>

Re: pq2_find_bridges hangs system

[Alex BASTOS]

Vitaly,

It didn't work. So I will check pq2ads_setup_pci to check if
some board specific issue is affected.

I will say you if I find anything

Thanks

Alex.

Citando Vitaly Bordug <vbordug@ru.mvista.com>:

> Alex,
> please probe this. If it will not help, pq2ads_setup_pci should be digged for
> some board specifics.
>
> Also, check if hose->set_cfg_type is 1 as done for ads8272.
>
> -------- Original Message --------
> Subject: [patch 01/34] ppc32: Fix incorrect PCI frequency value
> Date: Thu, 01 Dec 2005 00:51:15 -0800
> From: akpm@osdl.org
> To: torvalds@osdl.org
> CC: akpm@osdl.org, vbordug@ru.mvista.com, galak@kernel.crashing.org
>
>
> From: Vitaly Bordug <vbordug@ru.mvista.com>
>
> The time to wait after deasserting PCI_RST has been counted with incorrect
> value - this patch fixes the issue.
>
> Signed-off-by: Vitaly Bordug <vbordug@ru.mvista.com>
> Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
> Signed-off-by: Andrew Morton <akpm@osdl.org>
> ---
>
>  arch/ppc/syslib/m82xx_pci.c |    3 ++-
>  1 files changed, 2 insertions(+), 1 deletion(-)
>
> diff -puN arch/ppc/syslib/m82xx_pci.c~ppc32-fix-incorrect-pci-frequency-value
> arch/ppc/syslib/m82xx_pci.c
> ---
>
devel/arch/ppc/syslib/m82xx_pci.c~ppc32-fix-incorrect-pci-frequency-value	2005-11-30
> 23:58:00.000000000 -0800
> +++ devel-akpm/arch/ppc/syslib/m82xx_pci.c	2005-11-30 23:58:00.000000000
> -0800
> @@ -248,7 +248,8 @@ pq2ads_setup_pci(struct pci_controller *
>  	pci_div = ( (sccr & SCCR_PCI_MODCK) ? 2 : 1) *
>  			( ( (sccr & SCCR_PCIDF_MSK) >> SCCR_PCIDF_SHIFT) + 1);
>  	freq = (uint)((2*binfo->bi_cpmfreq)/(pci_div));
> -	time = (int)666666/freq;
> +	time = (int)66666666/freq;
> +
>  	/* due to PCI Local Bus spec, some devices needs to wait such a long
>  	time after RST 	deassertion. More specifically, 0.508s for 66MHz & twice
> more for 33 */
>  	printk("%s: The PCI bus is %d Mhz.\nWaiting %s after deasserting
> RST...\n",__FILE__,freq,
> _
>
>
>
> --
> Sincerely,
> Vitaly
>

Re: pq2_find_bridges hangs system

[Alex BASTOS]

Vitaly,

So, I have arrived to some conclusions.

1) With my previous kernel version (2.6.11) I had no problems
because it had CONFIG_PCI_8260 and CONFIG_PPC_INDIRECT_PCI unset.
So I think no effective read/write operation was executed, and so
that, no Machine Check.

In fact, this is the configuration I would prefer for my board. I have
to set CONFIG_PCI for enabling USB, but I don't want all the HW stuff
of the PCI. I can get these also with 2.6.15 if I modify Kconfig, to
allow me to unset PCI_8260 (and then PPC_INDIRECT_PCI) for my board.
With that, the problem dissapears and I can boot 2.6.15.

Shouldn't this (PCI_8260) be visible from xconfig for those like me
who wants USB (=> CONFIG_PCI) but don't really have any PCI device?

2) Although I am using Uboot 1.1.4, it is not top of git. I have
found your changes to support PCI on 8272ADS for u-boot are not
still applied on the version i am using. So, could this be causing
the problem? Is there any configuration done in u-boot required by
the PCI on the linux kernel to boot (BR3,OR3, EMR, ...)?

I should say that, on ADS, I have an older version of u-boot, 1.1.2,
and it boots OK.

3) I have seen that from u-boot, a reset occurs when I read Internal
Memory at offset 0x10904 (PCI CFG_DATA). From BDI, when I do the same
all PCI section on IM becomes zero. Is this a known behaviour? May this
reflect a hardware problem?

In conclusion, 1) solves my "must", a working board (without PCI).
But I still would like to know what am I doing so wrong with this.

Best regards,

Alex

Citando Alex BASTOS <alebas@televes.com>:

> Vitaly,
>
> It didn't work. So I will check pq2ads_setup_pci to check if
> some board specific issue is affected.
>
> I will say you if I find anything
>
> Thanks
>
> Alex.
>

Re: pq2_find_bridges hangs system

[Vitaly Bordug]

Alex BASTOS wrote:
> Vitaly,
> 
> So, I have arrived to some conclusions.
> 
> 1) With my previous kernel version (2.6.11) I had no problems
> because it had CONFIG_PCI_8260 and CONFIG_PPC_INDIRECT_PCI unset.
> So I think no effective read/write operation was executed, and so
> that, no Machine Check.
> 
> In fact, this is the configuration I would prefer for my board. I have
> to set CONFIG_PCI for enabling USB, but I don't want all the HW stuff
> of the PCI. I can get these also with 2.6.15 if I modify Kconfig, to
> allow me to unset PCI_8260 (and then PPC_INDIRECT_PCI) for my board.
> With that, the problem dissapears and I can boot 2.6.15.
> 
> Shouldn't this (PCI_8260) be visible from xconfig for those like me
> who wants USB (=> CONFIG_PCI) but don't really have any PCI device?
> 
Maybe, but I guess more correct is to deal with USB->PCI dependency.. 
Is it really needed(I am not USB expert)?
> 2) Although I am using Uboot 1.1.4, it is not top of git. I have
> found your changes to support PCI on 8272ADS for u-boot are not
> still applied on the version i am using. So, could this be causing
> the problem? Is there any configuration done in u-boot required by
> the PCI on the linux kernel to boot (BR3,OR3, EMR, ...)?
> 
> I should say that, on ADS, I have an older version of u-boot, 1.1.2,
> and it boots OK.
> 
My changes do not required for kernel to deal with PCI, that patch just allows access to PCI in 
U-Boot. Hence I might be useful if you'll head for resolving this issue which I guess unlikely to happen
> 3) I have seen that from u-boot, a reset occurs when I read Internal
> Memory at offset 0x10904 (PCI CFG_DATA). From BDI, when I do the same
> all PCI section on IM becomes zero. Is this a known behaviour? May this
> reflect a hardware problem?
> 
Sounds weird 
> In conclusion, 1) solves my "must", a working board (without PCI).
> But I still would like to know what am I doing so wrong with this.
> 
IMHO ability to disable PCI_8260 while PCI is on might be confusing, at least for upstream.



> Best regards,
> 
> Alex
> 
> Citando Alex BASTOS <alebas@televes.com>:
> 
>> Vitaly,
>>
>> It didn't work. So I will check pq2ads_setup_pci to check if
>> some board specific issue is affected.
>>
>> I will say you if I find anything
>>
>> Thanks
>>
>> Alex.
>>
> 
> 


-- 
Sincerely, 
Vitaly

[SOLVED] Re: pq2_find_bridges hangs system

[Alex BASTOS]

Vitaly,

> Maybe, but I guess more correct is to deal with USB->PCI dependency..
> Is it really needed(I am not USB expert)?

Neither am I. I guess for this Host Controler it is not needed at
HW level, but I am not sure why it is still required by the SW.


> > 3) I have seen that from u-boot, a reset occurs when I read Internal
> > Memory at offset 0x10904 (PCI CFG_DATA). From BDI, when I do the same
> > all PCI section on IM becomes zero. Is this a known behaviour? May this
> > reflect a hardware problem?
> >
> Sounds weird

Here is the problem. The cause for this weird behaviour is that I
had PCI_ARBITER_EN_  disabled. So, a HW problem at the end.
I had disabled it trying to reduce power compsumption due to the PCI,
as I am not going to use it. It seems it is not possible that way.
Any idea how to get this done?

> > In conclusion, 1) solves my "must", a working board (without PCI).
> > But I still would like to know what am I doing so wrong with this.
> >
> IMHO ability to disable PCI_8260 while PCI is on might be confusing, at least
> for upstream.

You are right.

Thanks so much for your help.

Best regards,

Alex

Re: [SOLVED] Re: pq2_find_bridges hangs system

[Vitaly Bordug]

Alex BASTOS wrote:
> Vitaly,
> 
>> Maybe, but I guess more correct is to deal with USB->PCI dependency..
>> Is it really needed(I am not USB expert)?
> 
> Neither am I. I guess for this Host Controler it is not needed at
> HW level, but I am not sure why it is still required by the SW.
> 
> 
>>> 3) I have seen that from u-boot, a reset occurs when I read Internal
>>> Memory at offset 0x10904 (PCI CFG_DATA). From BDI, when I do the same
>>> all PCI section on IM becomes zero. Is this a known behaviour? May this
>>> reflect a hardware problem?
>>>
>> Sounds weird
> 
> Here is the problem. The cause for this weird behaviour is that I
> had PCI_ARBITER_EN_  disabled. So, a HW problem at the end.
> I had disabled it trying to reduce power compsumption due to the PCI,
> as I am not going to use it. It seems it is not possible that way.
> Any idea how to get this done?
> 
Well, I guess the best you can do now - just use custom tree. I'll try to find 
good solution for such a case (PCI required by deps but not hw) next time I'll touch PCI.

>>> In conclusion, 1) solves my "must", a working board (without PCI).
>>> But I still would like to know what am I doing so wrong with this.
>>>
>> IMHO ability to disable PCI_8260 while PCI is on might be confusing, at least
>> for upstream.
> 
> You are right.
> 
> Thanks so much for your help.
> 
> Best regards,
> 
> Alex
> 
> 


-- 
Sincerely, 
Vitaly

Re: [SOLVED] Re: pq2_find_bridges hangs system

[Kumar Gala]

On Dec 14, 2005, at 8:14 AM, Vitaly Bordug wrote:

> Alex BASTOS wrote:
>> Vitaly,
>>> Maybe, but I guess more correct is to deal with USB->PCI  
>>> dependency..
>>> Is it really needed(I am not USB expert)?
>> Neither am I. I guess for this Host Controler it is not needed at
>> HW level, but I am not sure why it is still required by the SW.
>>>> 3) I have seen that from u-boot, a reset occurs when I read  
>>>> Internal
>>>> Memory at offset 0x10904 (PCI CFG_DATA). From BDI, when I do the  
>>>> same
>>>> all PCI section on IM becomes zero. Is this a known behaviour?  
>>>> May this
>>>> reflect a hardware problem?
>>>>
>>> Sounds weird
>> Here is the problem. The cause for this weird behaviour is that I
>> had PCI_ARBITER_EN_  disabled. So, a HW problem at the end.
>> I had disabled it trying to reduce power compsumption due to the PCI,
>> as I am not going to use it. It seems it is not possible that way.
>> Any idea how to get this done?

I'm guessing you dont have anything else doing arbitration on the bus.

- kumar

Re: [SOLVED] Re: pq2_find_bridges hangs system

[Alex BASTOS]

Kumar,

> >> Here is the problem. The cause for this weird behaviour is that I
> >> had PCI_ARBITER_EN_  disabled. So, a HW problem at the end.
> >> I had disabled it trying to reduce power compsumption due to the PCI,
> >> as I am not going to use it. It seems it is not possible that way.
> >> Any idea how to get this done?
>
> I'm guessing you dont have anything else doing arbitration on the bus.

You're right. I wasn't using the PCI at all.

>
> - kumar
>


Best regards,

Alex