| Message ID | 1342448756-7582-2-git-send-email-pbonzini@redhat.com |
|---|---|
| State | New |
| Headers | show |
On Mon, Jul 16, 2012 at 2:25 PM, Paolo Bonzini <pbonzini@redhat.com> wrote: > Support for START/STOP UNIT right now is limited to CD-ROMs. This is wrong, > since removable hard disks (in the real world: SD card readers) also support > it in pretty much the same way. I remember vaguely tuning a set of large SCSI hard disks (non-removable) so that they all didn't start immediately at the same time (which could have burned out the PSU) but only with START UNIT command. I think Linux or maybe even the BIOS started the drives (nicely in sequence) before accessing the drive. > > Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> > --- > hw/scsi-disk.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/hw/scsi-disk.c b/hw/scsi-disk.c > index bcec66b..42bae3b 100644 > --- a/hw/scsi-disk.c > +++ b/hw/scsi-disk.c > @@ -1251,7 +1251,7 @@ static int scsi_disk_emulate_start_stop(SCSIDiskReq *r) > bool start = req->cmd.buf[4] & 1; > bool loej = req->cmd.buf[4] & 2; /* load on start, eject on !start */ > > - if (s->qdev.type == TYPE_ROM && loej) { > + if ((s->features & (1 << SCSI_DISK_F_REMOVABLE)) && loej) { > if (!start && !s->tray_open && s->tray_locked) { > scsi_check_condition(r, > bdrv_is_inserted(s->qdev.conf.bs) > -- > 1.7.10.4 > > >
Il 23/07/2012 18:44, Blue Swirl ha scritto: >> > Support for START/STOP UNIT right now is limited to CD-ROMs. This is wrong, >> > since removable hard disks (in the real world: SD card readers) also support >> > it in pretty much the same way. > I remember vaguely tuning a set of large SCSI hard disks > (non-removable) so that they all didn't start immediately at the same > time (which could have burned out the PSU) but only with START UNIT > command. I think Linux or maybe even the BIOS started the drives > (nicely in sequence) before accessing the drive. Yes, all disks do start/stop. Removable disks support load and eject in addition. I'll fix the commit message. Paolo
diff --git a/hw/scsi-disk.c b/hw/scsi-disk.c index bcec66b..42bae3b 100644 --- a/hw/scsi-disk.c +++ b/hw/scsi-disk.c @@ -1251,7 +1251,7 @@ static int scsi_disk_emulate_start_stop(SCSIDiskReq *r) bool start = req->cmd.buf[4] & 1; bool loej = req->cmd.buf[4] & 2; /* load on start, eject on !start */ - if (s->qdev.type == TYPE_ROM && loej) { + if ((s->features & (1 << SCSI_DISK_F_REMOVABLE)) && loej) { if (!start && !s->tray_open && s->tray_locked) { scsi_check_condition(r, bdrv_is_inserted(s->qdev.conf.bs)
Support for START/STOP UNIT right now is limited to CD-ROMs. This is wrong, since removable hard disks (in the real world: SD card readers) also support it in pretty much the same way. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> --- hw/scsi-disk.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)