[PATCH v2] drivers/net/wireless/broadcom/b43: fix transmit failure when VT is switched

[PATCH v2] drivers/net/wireless/broadcom/b43: fix transmit failure when VT is switched

[Taketo Kabe]

From: Taketo Kabe <kabe@sra-tohoku.co.jp>

Fix for b43 wireless card stopping transmission when switching VTs.

Setup:
Using BCM4306 rev.03 chip based CardBus wireless card.
IRQ is shared with yenta (cardbus bridge) and i915 (display) driver.
For firmware, installed latest but dated openfwwf 5.2
(http://netweb.ing.unibs.it/~openfwwf/)

How-to-reproduce:
Do "ssh <NetBSD-remotehost>", then "ls -lR /" to generate traffic, then
repeatedly switch VTs by Alt-F1<>Alt-F2.
Eventually (within a minute) the card stops working.
You can receive traffic but no transmission.
For unknown reason it doesn't occur when just generating traffic by
"ssh <remotehost> ls -lR /".

With CONFIG_B43_DEBUG=y kernel config, when it stops,
the debug message shows
     kernel: b43-phy1 debug: Out of order TX status report on DMA ring 1. Expected 148, but got 180
The slot offset I observed so far was always 32.

When err_out2 is not set to make error messages successive,
the debug output will be like this:
kernel: b43-phy1 debug: Out of order TX status report on DMA ring 1. Expected 116, but got 148
kernel: b43-phy1 debug: Out of order TX status report on DMA ring 1. Expected 116, but got 150
kernel: b43-phy1 debug: Out of order TX status report on DMA ring 1. Expected 116, but got 120
kernel: b43-phy1 debug: Out of order TX status report on DMA ring 1. Expected 116, but got 152
kernel: b43-phy1 debug: Out of order TX status report on DMA ring 1. Expected 116, but got 122
kernel: b43-phy1 debug: Out of order TX status report on DMA ring 1. Expected 116, but got 154
kernel: b43-phy1 debug: Out of order TX status report on DMA ring 1. Expected 116, but got 124
kernel: b43-phy1 debug: Out of order TX status report on DMA ring 1. Expected 116, but got 156
kernel: b43-phy1 debug: Out of order TX status report on DMA ring 1. Expected 116, but got 126
The TX ring alternates between 2 sequences; the ring seems
to be completely confused. Controller restart is needed.

Workaround(1):
This problem doesn't occur when using propriatory firmware
you will extract by b43-fwcutter, so it may be a bug in
openfwwf firmware, as the comment in the b43_dma_handle_txstatus() suggests.
I wasn't able to find a bug in the terse openfwwf code though.

Workaround(2):
Using "pio=1" option to not use DMA makes this problem to
not occur.

Description of the patch:
This patch will forcibly reset the controller to make it
work again. Very kludgy and doesn't look right, but
the traffic will continue to flow.

Changes since last edition:
- Remove now unused err_out2 variable.

Signed-off-by: Taketo Kabe <kabe@sra-tohoku.co.jp>
---
diff -up ./drivers/net/wireless/broadcom/b43/dma.c.b43 ./drivers/net/wireless/broadcom/b43/dma.c
--- ./drivers/net/wireless/broadcom/b43/dma.c.b43	2018-05-04 15:18:12.000000000 +0900
+++ ./drivers/net/wireless/broadcom/b43/dma.c	2018-05-10 18:46:36.000000000 +0900
@@ -1484,7 +1484,7 @@ void b43_dma_handle_txstatus(struct b43_
  	int slot, firstused;
  	bool frame_succeed;
  	int skip;
-	static u8 err_out1, err_out2;
+	static u8 err_out1;

  	ring = parse_cookie(dev, status->cookie, &slot);
  	if (unlikely(!ring))
@@ -1518,13 +1518,13 @@ void b43_dma_handle_txstatus(struct b43_
  			}
  		} else {
  			/* More than a single header/data pair were missed.
-			 * Report this error once.
+			 * Report this error, and reset the controller to
+			 * revive operation.
  			 */
-			if (!err_out2)
-				b43dbg(dev->wl,
-				       "Out of order TX status report on DMA ring %d. Expected %d, but got %d\n",
-				       ring->index, firstused, slot);
-			err_out2 = 1;
+			b43dbg(dev->wl,
+			       "Out of order TX status report on DMA ring %d. Expected %d, but got %d\n",
+			       ring->index, firstused, slot);
+			b43_controller_restart(dev, "Out of order TX");
  			return;
  		}
  	}

-- 
kabe

Re: [PATCH v2] drivers/net/wireless/broadcom/b43: fix transmit failure when VT is switched

[Michael Büsch]

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On Thu, 10 May 2018 19:30:45 +0900
Taketo Kabe <kabe@sra-tohoku.co.jp> wrote:

> Signed-off-by: Taketo Kabe <kabe@sra-tohoku.co.jp>
> ---
> diff -up ./drivers/net/wireless/broadcom/b43/dma.c.b43 ./drivers/net/wireless/broadcom/b43/dma.c
> --- ./drivers/net/wireless/broadcom/b43/dma.c.b43	2018-05-04 15:18:12.000000000 +0900
> +++ ./drivers/net/wireless/broadcom/b43/dma.c	2018-05-10 18:46:36.000000000 +0900
> @@ -1484,7 +1484,7 @@ void b43_dma_handle_txstatus(struct b43_
>   	int slot, firstused;
>   	bool frame_succeed;
>   	int skip;
> -	static u8 err_out1, err_out2;
> +	static u8 err_out1;
> 
>   	ring = parse_cookie(dev, status->cookie, &slot);
>   	if (unlikely(!ring))
> @@ -1518,13 +1518,13 @@ void b43_dma_handle_txstatus(struct b43_
>   			}
>   		} else {
>   			/* More than a single header/data pair were missed.
> -			 * Report this error once.
> +			 * Report this error, and reset the controller to
> +			 * revive operation.
>   			 */
> -			if (!err_out2)
> -				b43dbg(dev->wl,
> -				       "Out of order TX status report on DMA ring %d. Expected %d, but got %d\n",
> -				       ring->index, firstused, slot);
> -			err_out2 = 1;
> +			b43dbg(dev->wl,
> +			       "Out of order TX status report on DMA ring %d. Expected %d, but got %d\n",
> +			       ring->index, firstused, slot);
> +			b43_controller_restart(dev, "Out of order TX");
>   			return;
>   		}
>   	}


Reviewed-by: Michael Büsch <m@bues.ch>

I think this is a good thing to have.
It improves robustness against firmware/DMA misbehavior.

-- 
Michael

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Re: [PATCH v2] drivers/net/wireless/broadcom/b43: fix transmit failure when VT is switched

[Kalle Valo]

Taketo Kabe <kabe@sra-tohoku.co.jp> writes:

> From: Taketo Kabe <kabe@sra-tohoku.co.jp>
>
> Fix for b43 wireless card stopping transmission when switching VTs.

The title is wrong, it should be:

b43: fix transmit failure when VT is switched

I can fix that during commit.

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches#commit_title_is_wrong


-- 
Kalle Valo

Re: [v2] b43: fix transmit failure when VT is switched

[Kalle Valo]

kabe@sra-tohoku.co.jp wrote:

> From: Taketo Kabe <kabe@sra-tohoku.co.jp>
> 
> Fix for b43 wireless card stopping transmission when switching VTs.
> 
> Setup:
> Using BCM4306 rev.03 chip based CardBus wireless card.
> IRQ is shared with yenta (cardbus bridge) and i915 (display) driver.
> For firmware, installed latest but dated openfwwf 5.2
> (http://netweb.ing.unibs.it/~openfwwf/)
> 
> How-to-reproduce:
> Do "ssh <NetBSD-remotehost>", then "ls -lR /" to generate traffic, then
> repeatedly switch VTs by Alt-F1<>Alt-F2.
> Eventually (within a minute) the card stops working.
> You can receive traffic but no transmission.
> For unknown reason it doesn't occur when just generating traffic by
> "ssh <remotehost> ls -lR /".
> 
> With CONFIG_B43_DEBUG=y kernel config, when it stops,
> the debug message shows
>      kernel: b43-phy1 debug: Out of order TX status report on DMA ring 1. Expected 148, but got 180
> The slot offset I observed so far was always 32.
> 
> When err_out2 is not set to make error messages successive,
> the debug output will be like this:
> kernel: b43-phy1 debug: Out of order TX status report on DMA ring 1. Expected 116, but got 148
> kernel: b43-phy1 debug: Out of order TX status report on DMA ring 1. Expected 116, but got 150
> kernel: b43-phy1 debug: Out of order TX status report on DMA ring 1. Expected 116, but got 120
> kernel: b43-phy1 debug: Out of order TX status report on DMA ring 1. Expected 116, but got 152
> kernel: b43-phy1 debug: Out of order TX status report on DMA ring 1. Expected 116, but got 122
> kernel: b43-phy1 debug: Out of order TX status report on DMA ring 1. Expected 116, but got 154
> kernel: b43-phy1 debug: Out of order TX status report on DMA ring 1. Expected 116, but got 124
> kernel: b43-phy1 debug: Out of order TX status report on DMA ring 1. Expected 116, but got 156
> kernel: b43-phy1 debug: Out of order TX status report on DMA ring 1. Expected 116, but got 126
> The TX ring alternates between 2 sequences; the ring seems
> to be completely confused. Controller restart is needed.
> 
> Workaround(1):
> This problem doesn't occur when using propriatory firmware
> you will extract by b43-fwcutter, so it may be a bug in
> openfwwf firmware, as the comment in the b43_dma_handle_txstatus() suggests.
> I wasn't able to find a bug in the terse openfwwf code though.
> 
> Workaround(2):
> Using "pio=1" option to not use DMA makes this problem to
> not occur.
> 
> Description of the patch:
> This patch will forcibly reset the controller to make it
> work again. Very kludgy and doesn't look right, but
> the traffic will continue to flow.
> 
> Signed-off-by: Taketo Kabe <kabe@sra-tohoku.co.jp>
> Reviewed-by: Michael Buesch <m@bues.ch>
> [kvalo@codeaurora.org: clean up commit log]

Failed to apply to wireless-drivers-next:

fatal: sha1 information is lacking or useless (drivers/net/wireless/broadcom/b43/dma.c).
error: could not build fake ancestor
Applying: b43: fix transmit failure when VT is switched
Patch failed at 0001 b43: fix transmit failure when VT is switched
The copy of the patch that failed is found in: .git/rebase-apply/patch

Please read:

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches#format_of_patches

Also the change log should be after --- line:

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches#changelog_missing

Patch set to Changes Requested.

-- 
https://patchwork.kernel.org/patch/10391617/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches

[PATCH v3] b43: fix transmit failure when VT is switched

[Taketo Kabe]

From: Taketo Kabe <kabe@sra-tohoku.co.jp>

Setup:
Using BCM4306 rev.03 chip based CardBus wireless card.
IRQ is shared with yenta (cardbus bridge) and i915 (display) driver.
For firmware, installed latest but dated openfwwf 5.2
(http://netweb.ing.unibs.it/~openfwwf/)

How-to-reproduce:
Do "ssh <NetBSD-remotehost>", then "ls -lR /" to generate traffic, then
repeatedly switch VTs by Alt-F1<>Alt-F2.
Eventually (within a minute) the card stops working.
You can receive traffic but no transmission.
For unknown reason it doesn't occur when just generating traffic by
"ssh <remotehost> ls -lR /".

With CONFIG_B43_DEBUG=y kernel config, when it stops,
the debug message shows
    kernel: b43-phy1 debug: Out of order TX status report on DMA ring 1. Expected 148, but got 180
The slot offset I observed so far was always 32.

When err_out2 is not set to make error messages successive,
the debug output will be like this:
kernel: b43-phy1 debug: Out of order TX status report on DMA ring 1. Expected 116, but got 148
kernel: b43-phy1 debug: Out of order TX status report on DMA ring 1. Expected 116, but got 150
kernel: b43-phy1 debug: Out of order TX status report on DMA ring 1. Expected 116, but got 120
kernel: b43-phy1 debug: Out of order TX status report on DMA ring 1. Expected 116, but got 152
kernel: b43-phy1 debug: Out of order TX status report on DMA ring 1. Expected 116, but got 122
kernel: b43-phy1 debug: Out of order TX status report on DMA ring 1. Expected 116, but got 154
kernel: b43-phy1 debug: Out of order TX status report on DMA ring 1. Expected 116, but got 124
kernel: b43-phy1 debug: Out of order TX status report on DMA ring 1. Expected 116, but got 156
kernel: b43-phy1 debug: Out of order TX status report on DMA ring 1. Expected 116, but got 126
The TX ring alternates between 2 sequences; the ring seems
to be completely confused. Controller restart is needed.

Workaround(1):
This problem doesn't occur when using propriatory firmware
you will extract by b43-fwcutter, so it may be a bug in
openfwwf firmware, as the comment in the b43_dma_handle_txstatus() suggests.
I wasn't able to find a bug in the terse openfwwf code though.

Workaround(2):
Using "pio=1" option to not use DMA makes this problem to
not occur.

Description of the patch:
This patch will forcibly reset the controller to make it
work again. Very kludgy and doesn't look right, but
the traffic will continue to flow.

Signed-off-by: Taketo Kabe <kabe@sra-tohoku.co.jp>
Reviewed-by: Michael Buesch <m@bues.ch>
---
 drivers/net/wireless/broadcom/b43/dma.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

Changes since last edition:
- Remove now unused err_out2 variable.
- Regenerated the patch using "git format-patch" against
  wireless-drivers-next.git .

diff --git a/drivers/net/wireless/broadcom/b43/dma.c b/drivers/net/wireless/broadcom/b43/dma.c
index 6837064..6b0e1ec 100644
--- a/drivers/net/wireless/broadcom/b43/dma.c
+++ b/drivers/net/wireless/broadcom/b43/dma.c
@@ -1484,7 +1484,7 @@ void b43_dma_handle_txstatus(struct b43_wldev *dev,
 	int slot, firstused;
 	bool frame_succeed;
 	int skip;
-	static u8 err_out1, err_out2;
+	static u8 err_out1;

 	ring = parse_cookie(dev, status->cookie, &slot);
 	if (unlikely(!ring))
@@ -1518,13 +1518,13 @@ void b43_dma_handle_txstatus(struct b43_wldev *dev,
 			}
 		} else {
 			/* More than a single header/data pair were missed.
-			 * Report this error once.
+			 * Report this error, and reset the controller to
+			 * revive operation.
 			 */
-			if (!err_out2)
-				b43dbg(dev->wl,
-				       "Out of order TX status report on DMA ring %d. Expected %d, but got %d\n",
-				       ring->index, firstused, slot);
-			err_out2 = 1;
+			b43dbg(dev->wl,
+			       "Out of order TX status report on DMA ring %d. Expected %d, but got %d\n",
+			       ring->index, firstused, slot);
+			b43_controller_restart(dev, "Out of order TX");
 			return;
 		}
 	}
-- 
kabe

Re: [v3] b43: fix transmit failure when VT is switched

[Kalle Valo]

kabe@sra-tohoku.co.jp wrote:

> From: Taketo Kabe <kabe@sra-tohoku.co.jp>
> 
> Setup:
> Using BCM4306 rev.03 chip based CardBus wireless card.
> IRQ is shared with yenta (cardbus bridge) and i915 (display) driver.
> For firmware, installed latest but dated openfwwf 5.2
> (http://netweb.ing.unibs.it/~openfwwf/)
> 
> How-to-reproduce:
> Do "ssh <NetBSD-remotehost>", then "ls -lR /" to generate traffic, then
> repeatedly switch VTs by Alt-F1<>Alt-F2.
> Eventually (within a minute) the card stops working.
> You can receive traffic but no transmission.
> For unknown reason it doesn't occur when just generating traffic by
> "ssh <remotehost> ls -lR /".
> 
> With CONFIG_B43_DEBUG=y kernel config, when it stops,
> the debug message shows
>     kernel: b43-phy1 debug: Out of order TX status report on DMA ring 1. Expected 148, but got 180
> The slot offset I observed so far was always 32.
> 
> When err_out2 is not set to make error messages successive,
> the debug output will be like this:
> kernel: b43-phy1 debug: Out of order TX status report on DMA ring 1. Expected 116, but got 148
> kernel: b43-phy1 debug: Out of order TX status report on DMA ring 1. Expected 116, but got 150
> kernel: b43-phy1 debug: Out of order TX status report on DMA ring 1. Expected 116, but got 120
> kernel: b43-phy1 debug: Out of order TX status report on DMA ring 1. Expected 116, but got 152
> kernel: b43-phy1 debug: Out of order TX status report on DMA ring 1. Expected 116, but got 122
> kernel: b43-phy1 debug: Out of order TX status report on DMA ring 1. Expected 116, but got 154
> kernel: b43-phy1 debug: Out of order TX status report on DMA ring 1. Expected 116, but got 124
> kernel: b43-phy1 debug: Out of order TX status report on DMA ring 1. Expected 116, but got 156
> kernel: b43-phy1 debug: Out of order TX status report on DMA ring 1. Expected 116, but got 126
> The TX ring alternates between 2 sequences; the ring seems
> to be completely confused. Controller restart is needed.
> 
> Workaround(1):
> This problem doesn't occur when using propriatory firmware
> you will extract by b43-fwcutter, so it may be a bug in
> openfwwf firmware, as the comment in the b43_dma_handle_txstatus() suggests.
> I wasn't able to find a bug in the terse openfwwf code though.
> 
> Workaround(2):
> Using "pio=1" option to not use DMA makes this problem to
> not occur.
> 
> Description of the patch:
> This patch will forcibly reset the controller to make it
> work again. Very kludgy and doesn't look right, but
> the traffic will continue to flow.
> 
> Signed-off-by: Taketo Kabe <kabe@sra-tohoku.co.jp>
> Reviewed-by: Michael Buesch <m@bues.ch>

Patch applied to wireless-drivers-next.git, thanks.

66cffd6daab7 b43: fix transmit failure when VT is switched

-- 
https://patchwork.kernel.org/patch/10396133/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches