[PATCH] bcm43xx: Fix machine check on PPC for version 1 PHY

[PATCH] bcm43xx: Fix machine check on PPC for version 1 PHY

[Larry Finger]

From: David Woodhouse <dwmw2@infradead.org>

Recent changes in the specs that were introduced in commit 
740ac4fb08866d702be90f167665d03759bd27d0 were incorrect and resulted in machine check
errors on the PPC architecture for G PHY's with a revision number equal to 1. The
two offending changes are reverted.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
---

John,

This fix should be applied to wireless-2.6 and set to 'upstream-fixes'. I hope is makes
it into 2.6.21 before the final release. The debugging of this issue was mostly done
by David with additional help by Pavil Roskin.

Larry


Index: wireless-2.6/drivers/net/wireless/bcm43xx/bcm43xx_phy.c
===================================================================
--- wireless-2.6.orig/drivers/net/wireless/bcm43xx/bcm43xx_phy.c
+++ wireless-2.6/drivers/net/wireless/bcm43xx/bcm43xx_phy.c
@@ -762,7 +762,7 @@ static void bcm43xx_phy_initb5(struct bc
 	if (radio->version == 0x2050)
 		bcm43xx_phy_write(bcm, 0x0038, 0x0667);
 
-	if (phy->type == BCM43xx_PHYTYPE_G) {
+	if (phy->connected) {
 		if (radio->version == 0x2050) {
 			bcm43xx_radio_write16(bcm, 0x007A,
 					      bcm43xx_radio_read16(bcm, 0x007A)
@@ -1197,7 +1197,7 @@ static void bcm43xx_phy_initg(struct bcm
 		bcm43xx_phy_write(bcm, 0x0811, 0x0400);
 		bcm43xx_phy_write(bcm, 0x0015, 0x00C0);
 	}
-	if (phy->connected) {
+	if (phy->rev >= 2 && phy->connected) {
 		tmp = bcm43xx_phy_read(bcm, 0x0400) & 0xFF;
 		if (tmp < 6) {
 			bcm43xx_phy_write(bcm, 0x04C2, 0x1816);

Re: [PATCH] bcm43xx: Fix machine check on PPC for version 1 PHY

[Michael Buesch]

On Sunday 25 March 2007 15:45, Larry Finger wrote:
> From: David Woodhouse <dwmw2@infradead.org>
> 
> Recent changes in the specs that were introduced in commit 
> 740ac4fb08866d702be90f167665d03759bd27d0 were incorrect and resulted in machine check
> errors on the PPC architecture for G PHY's with a revision number equal to 1. The
> two offending changes are reverted.

I'm not sure this patch is complete.
Joseph made changes to the specs that should fix the issue completely.
I didn't look at the changes, yet.

> Signed-off-by: David Woodhouse <dwmw2@infradead.org>
> Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
> ---
> 
> John,
> 
> This fix should be applied to wireless-2.6 and set to 'upstream-fixes'. I hope is makes
> it into 2.6.21 before the final release. The debugging of this issue was mostly done
> by David with additional help by Pavil Roskin.
> 
> Larry
> 
> 
> Index: wireless-2.6/drivers/net/wireless/bcm43xx/bcm43xx_phy.c
> ===================================================================
> --- wireless-2.6.orig/drivers/net/wireless/bcm43xx/bcm43xx_phy.c
> +++ wireless-2.6/drivers/net/wireless/bcm43xx/bcm43xx_phy.c
> @@ -762,7 +762,7 @@ static void bcm43xx_phy_initb5(struct bc
>  	if (radio->version == 0x2050)
>  		bcm43xx_phy_write(bcm, 0x0038, 0x0667);
>  
> -	if (phy->type == BCM43xx_PHYTYPE_G) {
> +	if (phy->connected) {
>  		if (radio->version == 0x2050) {
>  			bcm43xx_radio_write16(bcm, 0x007A,
>  					      bcm43xx_radio_read16(bcm, 0x007A)
> @@ -1197,7 +1197,7 @@ static void bcm43xx_phy_initg(struct bcm
>  		bcm43xx_phy_write(bcm, 0x0811, 0x0400);
>  		bcm43xx_phy_write(bcm, 0x0015, 0x00C0);
>  	}
> -	if (phy->connected) {
> +	if (phy->rev >= 2 && phy->connected) {
>  		tmp = bcm43xx_phy_read(bcm, 0x0400) & 0xFF;
>  		if (tmp < 6) {
>  			bcm43xx_phy_write(bcm, 0x04C2, 0x1816);
> 
> 

-- 
Greetings Michael.

Re: [PATCH] bcm43xx: Fix machine check on PPC for version 1 PHY

[David Woodhouse]

On Sun, 2007-03-25 at 16:13 +0200, Michael Buesch wrote:
> I'm not sure this patch is complete.
> Joseph made changes to the specs that should fix the issue completely.
> I didn't look at the changes, yet. 

I don't see relevant changes in the v3 specs. I was working empirically,
reverting parts of the large patch which broke it.

-- 
dwmw2

Re: [PATCH] bcm43xx: Fix machine check on PPC for version 1 PHY

[Larry Finger]

David Woodhouse wrote:
> On Sun, 2007-03-25 at 16:13 +0200, Michael Buesch wrote:
>> I'm not sure this patch is complete.
>> Joseph made changes to the specs that should fix the issue completely.
>> I didn't look at the changes, yet. 
> 
> I don't see relevant changes in the v3 specs. I was working empirically,
> reverting parts of the large patch which broke it.

There aren't any. Joseph is making the changes to the V4 specs, most of which are valid for V3 as
well. If I have any questions, I ask him privately.

Larry

Re: [PATCH] bcm43xx: Fix machine check on PPC for version 1 PHY

[David Woodhouse]

On Sun, 2007-03-25 at 13:23 -0500, Larry Finger wrote:
> There aren't any. Joseph is making the changes to the V4 specs, most
> of which are valid for V3 as well. If I have any questions, I ask him
> privately.

There is an important difference between the v3 and v4 specs in this
respect. Looking at http://bcm-v4.sipsolutions.net/802.11/PHY/Init/G I
see in =C2=A77a that we're only supposed to set PHY register 0x4cc if t=
he A
PHY revision is 5. The v3 specs seem to suggest that we should do that
whenever the revision is below 6 and not equal to 3.=20

The A PHY revision in my case is 2, and it's the access to PHY register
0x4CC which triggers the machine check.

--=20
dwmw2

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Re: [PATCH] bcm43xx: Fix machine check on PPC for version 1 PHY

[Larry Finger]

Michael Buesch wrote:
> On Sunday 25 March 2007 15:45, Larry Finger wrote:
>> From: David Woodhouse <dwmw2@infradead.org>
>>
>> Recent changes in the specs that were introduced in commit 
>> 740ac4fb08866d702be90f167665d03759bd27d0 were incorrect and resulted in machine check
>> errors on the PPC architecture for G PHY's with a revision number equal to 1. The
>> two offending changes are reverted.
> 
> I'm not sure this patch is complete.
> Joseph made changes to the specs that should fix the issue completely.
> I didn't look at the changes, yet.

Joseph has fixed the problem in initb5 (the first hunk), but the second hunk is still not in the new
specs. It was in the previous version in a slightly different form, but was found largely by trial
and error.

I would prefer that this patch go forward as is so that we don't end up with this bug in the
released version of 21.6.21. I am in the process of making the initg code match the current specs,
but that will certainly require more testing than I think we have time to complete before 2.6.21 is
released.

Larry

Re: [PATCH] bcm43xx: Fix machine check on PPC for version 1 PHY

[David Woodhouse]

On Sun, 2007-03-25 at 21:33 -0500, Larry Finger wrote:
> Joseph has fixed the problem in initb5 (the first hunk), but the second hunk is still not in the new
> specs. It was in the previous version in a slightly different form, but was found largely by trial
> and error.
> 
> I would prefer that this patch go forward as is so that we don't end up with this bug in the
> released version of 21.6.21. I am in the process of making the initg code match the current specs,
> but that will certainly require more testing than I think we have time to complete before 2.6.21 is
> released. 

FWIW I tried the mac80211 version (with v4 firmware) and saw very
similar machine checks, even after trying to apply the same 'fixes'.

-- 
dwmw2

Re: [PATCH] bcm43xx: Fix machine check on PPC for version 1 PHY

[Michael Buesch]

On Monday 26 March 2007 14:13, David Woodhouse wrote:
> On Sun, 2007-03-25 at 21:33 -0500, Larry Finger wrote:
> > Joseph has fixed the problem in initb5 (the first hunk), but the second hunk is still not in the new
> > specs. It was in the previous version in a slightly different form, but was found largely by trial
> > and error.
> > 
> > I would prefer that this patch go forward as is so that we don't end up with this bug in the
> > released version of 21.6.21. I am in the process of making the initg code match the current specs,
> > but that will certainly require more testing than I think we have time to complete before 2.6.21 is
> > released. 
> 
> FWIW I tried the mac80211 version (with v4 firmware) and saw very
> similar machine checks, even after trying to apply the same 'fixes'.

logs...

-- 
Greetings Michael.

Re: [PATCH] bcm43xx: Fix machine check on PPC for version 1 PHY

[Pavel Roskin]

Hi, Larry!

That was quick!  I confirm that the patch fixes the machine check for me.  The
driver is working, even with WEP.  To prove my point, I'll send this message
over the fixed driver, so if you can read it, you have made an excellent job :)

--
Regards,
Pavel Roskin

Re: [PATCH] bcm43xx: Fix machine check on PPC for version 1 PHY

[Larry Finger]

Pavel Roskin wrote:
> Hi, Larry!
> 
> That was quick!  I confirm that the patch fixes the machine check for me.  The
> driver is working, even with WEP.  To prove my point, I'll send this message
> over the fixed driver, so if you can read it, you have made an excellent job :)

Thanks, but David Woodhouse deserves the credit.

In future cases, I'll send any changes that modify phy->rev == 1 behavior past you and David before
submitting. Too bad that one doesn't get the machine check on x86 architectures as I also have a rev
1 cards.

Larry