On Thu, 5 Feb 2009, Andrew Morton wrote: > On Tue, 3 Feb 2009 15:05:58 +0100 > Jean Pihet <[email protected]> wrote: > > > + while (OMAP_HSMMC_READ(host->base, > > + SYSCTL) & SRD) > > + ; > > Is a __raw_readl() sufficient to prevent the cpu from burning up here, > or should we add cpu_relax()?
The __raw_readl() should be sufficient. The MMC controller is located on the L4 CORE interconnect, so the round trip latency for the read from MMC is at least 90 ns, while the CPU cycle time is only about 1 to 2 ns. > An infinite loop which assumes the hardware is perfect is always a > worry. But I see the driver already does that, so we're no worse off.. - Paul -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
