On Fri, 2012-12-14 at 17:11 +0000, Russell King - ARM Linux wrote: > On Fri, Dec 14, 2012 at 03:38:46PM +0000, Pawel Moll wrote: > > The Versatile Express IOFPGA as shipped on VECD 5.0 (bitfiles v108/208 > > and v116/216) contains a modified version of the PL180 MMCI, with > > PeriphID Configuration value changed to 0x2. > > > > This version adds an optional "hardware flow control" feature. When > > enabled MMC card clock will be automatically disabled when FIFO is > > about to over/underflow and re-enabled once the host retrieved some > > data. This makes the controller immune to over/underrun errors caused > > by big interrupt handling latencies. > > Wrong. It doesn't make it "immune", it just makes it less likely to > occur - you just need a heavier workload to provoke it. Why do you think so? The MMC clock is cut off when the FIFO gets full, so there will be no more data received - no overflow is possible. Paweł -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
