On 09/14/2012 04:17 PM, James Bottomley wrote: >> Just read the SPC-4 spec, in section 5.12.3, it has words like this: >> >> Logical units that contain cache memory shall write all cached data to >> the medium for the logical unit(e.g., as a logical unit would do in >> response to a SYNCHRONIZE CACHE command as described SBC-3) prior to >> entering into any power condition that prevents accessing the >> media(e.g., before a hard drive stops its spindle motor during a change >> to the standby power condition). >> >> So this looks like cache needs to be synced before the device enter >> standby/stopped power condition. Or do I miss somthing? > > Um, no it says the device shall do the sync on its own (as though it > received a sync cache). That section says the device shall be > responsible for cache management in the power states. Oh, I thought it was the host software's responsibility, thanks for the explanation. So if we program the device to let it enter standby/stopped power condition with the start_stop_unit command, do we need to sync the cache? Thanks, Aaron -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
