2013/5/5 Rafał Miłecki <zajec5@xxxxxxxxx>: > 2013/4/23 Thommy Jakobsson <thommyj@xxxxxxxxx>: >> Add handling of rx descriptor underflow. This fixes a fault that could >> happen on slow machines, where data is received faster than the CPU can >> handle. In such a case the device will use up all rx descriptors and >> refuse to send any more data before confirming that it is ok. This >> patch enables necessary interrupt to discover such a situation and will >> handle them by dropping everything in the ring buffer. > > Thommy: does it mean firmware actually ignores what we write to the > B43_DMA64_RXINDEX (recently renamed to the B43_DMA64_RXSTOPINDEX)? Is > our set_current_rxslot and op64_set_current_rxslot (same for 32bit > version) useless in this situation? I've also grab some old logs from BCM4311 from wl driver. DMA setup: write32 0xfaafc210 <- 0x0000083d B43_DMA32_RXCTL write32 0xfaafc214 <- 0x5581e000 B43_DMA32_RXRING write32 0xfaafc218 <- 0x00000100 B43_DMA32_RXINDEX While running: read32 0xfaafc21c -> 0x02001018 B43_DMA32_RXSTATUS read32 0xfaafc21c -> 0x02001018 B43_DMA32_RXSTATUS read32 0xfaafc180 -> 0x0006230f read32 0xfaafc184 -> 0x00000000 write32 0xfaafc218 <- 0x00000118 B43_DMA32_RXINDEX (...) read32 0xfaafc21c -> 0x02801020 B43_DMA32_RXSTATUS read32 0xfaafc21c -> 0x02801020 B43_DMA32_RXSTATUS read32 0xfaafc180 -> 0x00064c28 read32 0xfaafc184 -> 0x00000000 write32 0xfaafc218 <- 0x00000120 B43_DMA32_RXINDEX Interesting part is that they write amount of slots + slot index to the B43_DMA32_RXINDEX (like 0x120 instead of 0x20). May be worth investigating. -- Rafał -- 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
