On Thursday 05 February 2009 21:32:03 Paul Walmsley wrote: > On Thu, 5 Feb 2009, Andrew Morton wrote: > > On Tue, 3 Feb 2009 15:05:58 +0100 > > > > Jean Pihet <jpihet@xxxxxxxxxx> 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. Ok. > > > 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.. Do you want a finite loop with udelay in it? I located 4 places were this could be used. If so I can generate a new patch for that. > > - Paul Regards, Jean -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
