[LinuxBIOS] new feature - CrushK8-04 USB1 Controller Reset

[Roman Kononov]

I have Sun Ultra40 workstation. Southbridge is nVidia CrushK8-04/nforce
2200 (too many names, sounds like a criminal).

1) Linuxbios loads kernel A; kernel A loads kernel B. Everything works fine.

2) Then I push the reset button.

3) Linuxbios loads kernel A; kernel A loads kernel B. Kernel B complains
about wrong checksum of the mptable and crushes later.

An investigation showed that in 3), short after kernel A (v2.6.19.2) sets
the Bus Master Enable bit of the nVidia's USB1 controller (pci_set_master()),
the mptable gets two bytes at physical address 0x80 damaged.

Nothing is plugged to the USB ports. Other two Sun workstations had the same
behavior. This does not make sense to me unless the controller has a HW bug.

I believe, this should better be fixed in the kernel USB driver.

For now this patch offers a possibility for linuxbios to reset the USB
controller by setting HostControllerReset bit in HcCommandStatus Register.
It is enablead by using 'register "usb1_hc_reset"="1"' in 'chip
southbridge/nvidia/ck804' section of the mainboard's Config.lb.

Signed-off-by: Roman Kononov

[LinuxBIOS] new feature - CrushK8-04 USB1 Controller Reset

[ron minnich]

Hi Roman, this patch looks fine save for one thing: I believe that the
// comments were supposed to be deprecated. I can not find a reference
for this, however; anybody care to correct me?

signed,

a former // coment user

[LinuxBIOS] new feature - CrushK8-04 USB1 Controller Reset

[Uwe Hermann]

Hi,

On Fri, Feb 02, 2007 at 10:40:34AM -0700, ron minnich wrote:
> Hi Roman, this patch looks fine save for one thing: I believe that the
> // comments were supposed to be deprecated. I can not find a reference
> for this, however; anybody care to correct me?

Well, not sure. // comments are valid in C++, but not (ANSI?) C as far
as I know. But in practice compilers allow both, except if you pass some
command line options like -pedantic and others...

Uwe.

[LinuxBIOS] new feature - CrushK8-04 USB1 Controller Reset

[Carl-Daniel Hailfinger]

Uwe Hermann wrote:
> Hi,
>
> On Fri, Feb 02, 2007 at 10:40:34AM -0700, ron minnich wrote:
> > Hi Roman, this patch looks fine save for one thing: I believe that the
> > // comments were supposed to be deprecated. I can not find a reference
> > for this, however; anybody care to correct me?
>
> Well, not sure. // comments are valid in C++, but not (ANSI?) C as far
> as I know. But in practice compilers allow both, except if you pass some
> command line options like -pedantic and others...

IIRC the C99 standard is the first C standard to allow // comments.

Regards,
Carl-Daniel

[LinuxBIOS] new feature - CrushK8-04 USB1 Controller Reset

[Roman Kononov]

On 02/02/2007 12:08 PM, Carl-Daniel Hailfinger wrote:
> IIRC the C99 standard is the first C standard to allow // comments.

I vote for allowing // comments since:

1. they are a C standard
2. they do not clutter so much
3. they make life easier for many people
4. the current code has too many GCC-specific things anyway

Roman

[LinuxBIOS] new feature - CrushK8-04 USB1 Controller Reset

[Uwe Hermann]

Hi,

On Fri, Feb 02, 2007 at 02:28:28PM -0600, Roman Kononov wrote:
> On 02/02/2007 12:08 PM, Carl-Daniel Hailfinger wrote:
> > IIRC the C99 standard is the first C standard to allow // comments.
>
> I vote for allowing // comments since:

Yeah, I agree. This is not so critical, IMHO. If we really care, we can
always replace them later... We got more important things to do right now :)

Besides, we already have lots of // comments in the code anyway.
> the current code has too many GCC-specific things anyway

This is more important IMHO than the // comments. We should keep
LinuxBIOS as compiler-/toolchain-independant as possible (if we can).

Patches to improve the situation are welcome :)

Uwe.

[LinuxBIOS] new feature - CrushK8-04 USB1 Controller Reset

[ron minnich]

On 2/1/07, Roman Kononov  wrote:
> I have Sun Ultra40 workstation. Southbridge is nVidia CrushK8-04/nforce
> 2200 (too many names, sounds like a criminal).
>
> Linuxbios loads kernel A; kernel A loads kernel B. Everything works fine.
>
> Then I push the reset button.
>
> Linuxbios loads kernel A; kernel A loads kernel B. Kernel B complains
>
> about wrong checksum of the mptable and crushes later.
>
> An investigation showed that in 3), short after kernel A (v2.6.19.2) sets
> the Bus Master Enable bit of the nVidia's USB1 controller (pci_set_master()),
> the mptable gets two bytes at physical address 0x80 damaged.
>
> Nothing is plugged to the USB ports. Other two Sun workstations had the same
> behavior. This does not make sense to me unless the controller has a HW bug.
>
> I believe, this should better be fixed in the kernel USB driver.
>
> For now this patch offers a possibility for linuxbios to reset the USB
> controller by setting HostControllerReset bit in HcCommandStatus Register.
> It is enablead by using 'register "usb1_hc_reset"="1"' in 'chip
> southbridge/nvidia/ck804' section of the mainboard's Config.lb.
>
> Signed-off-by: Roman Kononov

Acked-by: Ronald G. Minnich 
Committed revision 2546.