2.6.25-stable review patch. If anyone has any objections, please let us know. ------------------ From: Michael Buesch <mb@xxxxxxxxx> commit 98a3b2fe435ae76170936c14f5c9e6a87548e3ef upstream. This removes a WARN_ON that is responsible for the following koops: http://www.kerneloops.org/searchweek.php?search=b43_generate_noise_sample The comment in the patch describes why it's safe to simply remove the check. Signed-off-by: Michael Buesch <mb@xxxxxxxxx> Signed-off-by: John W. Linville <linville@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx> --- drivers/net/wireless/b43/b43.h | 1 - drivers/net/wireless/b43/main.c | 16 ++++++++++------ 2 files changed, 10 insertions(+), 7 deletions(-) --- a/drivers/net/wireless/b43/b43.h +++ b/drivers/net/wireless/b43/b43.h @@ -596,7 +596,6 @@ struct b43_dma { /* Context information for a noise calculation (Link Quality). */ struct b43_noise_calculation { - u8 channel_at_start; bool calculation_running; u8 nr_samples; s8 samples[8][4]; --- a/drivers/net/wireless/b43/main.c +++ b/drivers/net/wireless/b43/main.c @@ -1027,7 +1027,6 @@ static void b43_generate_noise_sample(st b43_jssi_write(dev, 0x7F7F7F7F); b43_write32(dev, B43_MMIO_MACCMD, b43_read32(dev, B43_MMIO_MACCMD) | B43_MACCMD_BGNOISE); - B43_WARN_ON(dev->noisecalc.channel_at_start != dev->phy.channel); } static void b43_calculate_link_quality(struct b43_wldev *dev) @@ -1036,7 +1035,6 @@ static void b43_calculate_link_quality(s if (dev->noisecalc.calculation_running) return; - dev->noisecalc.channel_at_start = dev->phy.channel; dev->noisecalc.calculation_running = 1; dev->noisecalc.nr_samples = 0; @@ -1053,9 +1051,16 @@ static void handle_irq_noise(struct b43_ /* Bottom half of Link Quality calculation. */ + /* Possible race condition: It might be possible that the user + * changed to a different channel in the meantime since we + * started the calculation. We ignore that fact, since it's + * not really that much of a problem. The background noise is + * an estimation only anyway. Slightly wrong results will get damped + * by the averaging of the 8 sample rounds. Additionally the + * value is shortlived. So it will be replaced by the next noise + * calculation round soon. */ + B43_WARN_ON(!dev->noisecalc.calculation_running); - if (dev->noisecalc.channel_at_start != phy->channel) - goto drop_calculation; *((__le32 *)noise) = cpu_to_le32(b43_jssi_read(dev)); if (noise[0] == 0x7F || noise[1] == 0x7F || noise[2] == 0x7F || noise[3] == 0x7F) @@ -1096,11 +1101,10 @@ static void handle_irq_noise(struct b43_ average -= 48; dev->stats.link_noise = average; - drop_calculation: dev->noisecalc.calculation_running = 0; return; } - generate_new: +generate_new: b43_generate_noise_sample(dev); } -- -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
