-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 On 01/07/2014 09:36 PM, Aaron Lu wrote: > I think the host controller can decide not to power all its ports, > only when a specific reg in the port's memory range is set, it will > give power to that port and thus spin up the drive. Makes sense? The port doesn't supply power to the drive, it gets it straight from the system PSU. > Oh, of course, my stupid :-) Then I suddenly think my patches can > kind of work - let's say we have done the hdparm setting thing > before suspend and the disk will be spun up in standby mode next > time it is powered. Then during system resume phase, remove the > pm_request_resume call in both SCSI and ATA's system resume > callback, - if the disk is powered, it will be in standby mode and > its runtime status is RPM_SUSPENDED, match its real status(sort > of); - if the disk is not powered due to some host feature or > whatever, it will be in unpowered mode and its runtime status is > RPM_SUSPENDED, still match its real status. Right, but if the disk is a run of the mill ATA disk not configured for power up in standby, then you end up with runtime pm saying that it is suspended, when in fact, it spun up on its own and is sitting there waiting for commands. The PuiS setting isn't something we can or want to twiggle on our own during suspend, that's an admin decision that they set more or less permanently either with hdparm or the hardware jumper. We just need to detect what the drive has done and update the runtime pm status to match. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.14 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQEcBAEBCgAGBQJSzOEaAAoJEI5FoCIzSKrwIVoH/1sszQsK1buyg9hDvemd84m6 EMkMUsab4qYZlxGcQpnUUlJbQpGKnhDXjxBstjD8zfnC6WQfOCySTqkqBzZqEXzE QEt5IV7mWn43tGbu4pyYlw4SrEOmOmmYJxl5yh033MAPNsP/rhToXZoEPOTRCro4 GdkZpxx0A9Y/rnzLN29RoFw41T5G4aG0O7FyTuZGPW/uWhhdUqxpUQt7ACCD+fdD GaHWf2WInU7vSrDcg6daxvarqQ8GJavc1rafM45EkGMCzGwRhvIR+PCBk8E9t1qA eB/1b9q8DiBJVCiMxcZVOLY8PY0bm1eBRRqhMef0l7Ppvl8N23f84o7tcN57lWY= =RCPv -----END PGP SIGNATURE----- -- 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
