| The following patchset cleans up the atmel_serial driver a bit, | moves a significant portion of the interrupt handler into a tasklet, | and adds DMA support. This is the result of a combined effort by Chip | Coldwell, Remy Bohmer and me. The patches should apply cleanly onto | Linus' latest git tree. | | With DMA, I see transfer rates around 92 kbps when transferring a big | file using ZModem (both directions are roughly the same.) |
The start and stop bits will use 20 % of the bit rate so the teoretical max throughput at 115,200 BAUD is 115,200 * 0,8 = 92160 bps. What would be interesting is to figure out if we can get reliable transmission at higher frequencies - 230/460/921 kbps. | Note that break and error handling doesn't work too well with DMA | enabled. This is a common problem with all the efforts I've seen | adding DMA support to this driver (including my own). The PDC error | handling also accesses icount without locking. I'm tempted to just | ignore the problem for now and hopefully come up with a solution | later. Have told the guys responsible for the USART IP block we need to improve the H/W for error control for the last 3-4 years. Why not at 120000 gates/sq mm, add error counters??? Best Regards Ulf Samuelsson -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/