[patch]:Skip VC1 to fix dbm690t hanging

[Bao, Zheng]

After I modify the pci_ext_read_config32 and pci_ext_read_config32, the
step 6a
starts to play its role. Then the system hangs at HDA init. I dont know
what the
VC1 is. The RPR says "Optional Features (only needed if CMOS option is
enabled)"
in 5.10.2. Before I know what it is, I think it is better to skip it.

Tested on dbm690t.

Signed-off-by: Zheng Bao

--------------------

Index: src/southbridge/amd/rs690/rs690_pcie.c
===================================================================
--- src/southbridge/amd/rs690/rs690_pcie.c	(revision 4338)
+++ src/southbridge/amd/rs690/rs690_pcie.c	(working copy)
@@ -276,6 +276,7 @@
    /* step 6a: VCI */
    sb_dev = dev_find_slot(0, PCI_DEVFN(8, 0));
    if (port == 8) {
+#if 0
    	/* Clear bits 7:1 */
    	pci_ext_write_config32(nb_dev, sb_dev, 0x114, 0x3f << 1,
0 << 1);
    	/* Maps Traffic Class 1-7 to VC1 */
@@ -284,7 +285,7 @@
    	pci_ext_write_config32(nb_dev, sb_dev, 0x120, 7 << 24, 1
<< 24);
    	/* Enables VC1 */
    	pci_ext_write_config32(nb_dev, sb_dev, 0x120, 1 << 31, 1
<< 31);
-#if 0
+
    	do {
    		reg16 = pci_ext_read_config32(nb_dev, sb_dev,
0x124);
    		reg16 &= 0x2;

[Carl-Daniel Hailfinger]

On 05.06.2009 11:17, Bao, Zheng wrote:
> After I modify the pci_ext_read_config32 and pci_ext_read_config32, the
> step 6a
> starts to play its role. Then the system hangs at HDA init. I dont know
> what the
> VC1 is. The RPR says "Optional Features (only needed if CMOS option is
> enabled)"
> in 5.10.2. Before I know what it is, I think it is better to skip it.
>
> Tested on dbm690t.
>
> Signed-off-by: Zheng Bao

If you add a comment before the #if 0 which says that this code causes a
hang on HDA init, the patch is
Acked-by: Carl-Daniel Hailfinger

Regards,
Carl-Daniel

[Rudolf Marek]

Hi all,

VC is virtual channel. Its used for isochronous transfer of data to sound card. 
The virtual channel guarantee "on time" delivery.In other words it sets up a 
channel for data to sound card, which means that that arrive in time and there 
will be no interruptions in audio stream.

Unfortunately I never played with that. This is all I know ;)

Rudolf

[Rudolf Marek]

Hi again,

http://www.microsoft.com/whdc/connect/pci/wlp_interrupt.mspx

Here is some writeup. HD Audio is a special case.

Rudolf

[Bao, Zheng]

The comment was added and

Commited to r4339.

I also add some comment from Rudolf in svn message.

Zheng

-----Original Message-----
From: Carl-Daniel Hailfinger [mailto:[e-mail]] 
Sent: Friday, June 05, 2009 5:22 PM
To: Bao, Zheng
Cc: [e-mail]
Subject: Re: [coreboot] [patch]:Skip VC1 to fix dbm690t hanging

On 05.06.2009 11:17, Bao, Zheng wrote:
> After I modify the pci_ext_read_config32 and pci_ext_read_config32,

the
> step 6a
> starts to play its role. Then the system hangs at HDA init. I dont

know
> what the
> VC1 is. The RPR says "Optional Features (only needed if CMOS option is
> enabled)"
> in 5.10.2. Before I know what it is, I think it is better to skip it.
>
> Tested on dbm690t.
>
> Signed-off-by: Zheng Bao

If you add a comment before the #if 0 which says that this code causes a
hang on HDA init, the patch is
Acked-by: Carl-Daniel Hailfinger

Regards,
Carl-Daniel