On Tue, Sep 18, 2012 at 09:30:11AM +0200, Oliver Neukum wrote: > On Tuesday 18 September 2012 15:00:28 Aaron Lu wrote: > > When scsi device received stop command, it will take care of its > > internal cache before enters stopped power condition. This command is > > translated to standby immediate in libata-scsi, but standby doesn't > > imply flush cache for ATA device, so to issue stop command to ATA > > device, an additional flush cache has to be issued. > > Why not just set WCE? This flag is used for devices whose WCE bit is set. This flag means, when we are to issue a scsi stop command, we need to issue an additional sync cache command first. For scsi device, per the spec, there is no such need as the device will take care of its internal cache when going to stop power condition. But for ata device, the stop command is translated to standby immediate, and we have to flush the internal cache before enter standby. -Aaron -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
