b43: fix transmit failure when VT is switched
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> Signed-off-by:
Kalle Valo <kvalo@codeaurora.org>
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