On Wed, 2012-02-15 at 14:06 +0800, Aaron Lu wrote: > Hi, > > Good work, I'm also working on ZPODD for AMD platforms, some comments below. Great :) > > On Mon, Feb 13, 2012 at 5:11 PM, Lin Ming <ming.m.lin@xxxxxxxxx> wrote: > > ZPODD(Zero Power Optical Disk Drive) is a new feature in > > SATA 3.1 specification. It provides a way to power off unused CDROM. > > I don't see anywhere in the sata 3.1 spec mentioned how to power off the > cdrom, the only relevant content is the newly defined device attention pin, > which is used to notify the host that this powered off device needs attention. > Or do I miss something? You're right. > > > > > CDROM is powered off by executing ACPI power resource's _OFF method. > > > > AMD has a different implementation to power off the CDROM, I'll need to > prepare another patch based on yours. Could you share AMD's implementation? > > > When CDROM is powered off(D3Cold state), inserting disk will trigger a > > wakeup event(GPE). GPE AML handler notifies the associated device. Then > > CDROM is resumed in the notify handler. > > > > Signed-off-by: Lin Ming <ming.m.lin@xxxxxxxxx> > > --- > > drivers/ata/libata-acpi.c | 64 +++++++++++++++++++++++++++++++++++++------- > > drivers/scsi/sr.c | 39 +++++++++++++++++++++++++++ > > drivers/scsi/sr.h | 3 ++ > > 3 files changed, 95 insertions(+), 11 deletions(-) > > > > diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c > > index 5fc97d2..bf4eace 100644 > > --- a/drivers/scsi/sr.c > > +++ b/drivers/scsi/sr.c > > @@ -716,6 +752,9 @@ static int sr_probe(struct device *dev) > > disk->flags |= GENHD_FL_REMOVABLE; > > add_disk(disk); > > > > + if (device_run_wake(dev)) > > + cd->zpodd = 1; > > + > > For a cd to support zero power, it has to support device attention pin. > If it does not support that, once it is powered off, it can't be power up > back. So I don't think device_run_wake is enough to set the zpodd flag, > unless your firmware has done the check and created the acpi table > according to the result. Is it the case? I should add device attention pin check. Thanks for the comments. Lin Ming > > Thanks, > 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
