On Wed, 14 Jul 2010 17:07:28 +0400, Anton Vorontsov <[email protected]> wrote: > Hi all, > > Currently the sdhci driver does everything in the atomic context. > And what is worse, PIO transfers are made from the IRQ handler. > > This causes huge latencies (up to 120 ms). On some P2020 SOCs, > DMA and card detection is broken, which means that kernel polls > for the card via PIO transfers every second. Needless to say > that this is quite bad. > > So, this patch set reworks sdhci code to avoid atomic context, > almost completely. We only do two device memory operations > in the atomic context, and all the rest is threaded. > > I noticed no throughput drop neither with PIO transfers nor > with DMA (tested on MPC8569E CPU), while latencies should be > greatly improved.
I haven't had time to read these patches in detail yet but they all seem to be sensible changes. A very nice series! -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
