On Tuesday 04 September 2012 22:24:34 Aaron Lu wrote:
> From: Aaron Lu <aaron.lu@xxxxxxxxx>
>
> The ODD will be placed into suspend state when:
> 1 For tray type ODD, no media inside and door closed;
> 2 For slot type ODD, no media inside;
> And together with ACPI, when we suspend the ODD's parent(the port it
> attached to), we will omit the power altogether to reduce power
> consumption(done in libata-acpi.c).
Well, this is quite a layering violation. You encode that specific requirement
in the generic sr_suspend()
> The ODD can be resumed either by user or by software.
>
> For user to resume the suspended ODD:
> 1 For tray type ODD, press the eject button;
> 2 For slot type ODD, insert a disc;
> Once such events happened, an ACPI notification will be sent and in our
> handler, we will resume the ODD(again in libata-acpi.c).
> This kind of resume requires platform and device support and is
> reflected by the can_power_off flag.
>
> For software to resume the suspended ODD, we did this in ODD's
> open/release and check_event function.
>
> Signed-off-by: Aaron Lu <aaron.lu@xxxxxxxxx>
> ---
> drivers/ata/libata-acpi.c | 6 ++--
> drivers/scsi/sr.c | 76 ++++++++++++++++++++++++++++++++++++++++++++--
> include/scsi/scsi_device.h | 1 +
> 3 files changed, 79 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/ata/libata-acpi.c b/drivers/ata/libata-acpi.c
> index 902b5a4..64ba43d 100644
> --- a/drivers/ata/libata-acpi.c
> +++ b/drivers/ata/libata-acpi.c
> @@ -985,8 +985,10 @@ static void ata_acpi_wake_dev(acpi_handle handle, u32 event, void *context)
> struct ata_device *ata_dev = context;
>
> if (event == ACPI_NOTIFY_DEVICE_WAKE && ata_dev &&
> - pm_runtime_suspended(&ata_dev->sdev->sdev_gendev))
> - scsi_autopm_get_device(ata_dev->sdev);
> + pm_runtime_suspended(&ata_dev->sdev->sdev_gendev)) {
> + ata_dev->sdev->wakeup_by_user = 1;
That flag is badly named. Something like "insert_event_during_suspend"
would be better.
[..]
> +static int sr_suspend(struct device *dev, pm_message_t msg)
> +{
> + int suspend;
> + struct scsi_sense_hdr sshdr;
> + struct scsi_cd *cd = dev_get_drvdata(dev);
> +
> + /* no action for system pm */
> + if (!PMSG_IS_AUTO(msg))
> + return 0;
> +
> + /*
> + * ODD can be runtime suspended when:
> + * tray type: no media inside and tray closed
> + * slot type: no media inside
> + */
> + scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr);
> +
> + if (cd->cdi.mask & CDC_CLOSE_TRAY)
> + /* no media for caddy/slot type ODD */
> + suspend = scsi_sense_valid(&sshdr) && sshdr.asc == 0x3a;
> + else
> + /* no media and door closed for tray type ODD */
> + suspend = scsi_sense_valid(&sshdr) && sshdr.asc == 0x3a &&
> + sshdr.ascq == 0x01;
That requirement is valid for a specific type of disk. You cannot put it
into generic sd_suspend(). And even so I don't see why you wouldn't
want to suspend for example a drive with an inserted but unopened disk.
> +
> + if (!suspend)
> + return -EBUSY;
> +
> + return 0;
> +}
Regards
Oliver
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